IMPROVING EXIT RAMP VISIBILITY IN WORK ZONES. Proposal submitted by: Cleveland State University and Ohio University. Principal Investigators:

Transcription

1 IMPROVING EXIT RAMP VISIBILITY IN WORK ZONES Proposal submitted by: Cleveland State University and Ohio University Principal Investigators: Stephen F. Duffy, Ph.D., P.E., F.ASCE for Cleveland State University Deborah S. McAvoy, Ph.D., P.E., PTOE for Ohio University Partnering Agency: Cleveland State University s University Transportation Center Partnering Agency Technical Contact: Stephen F. Duffy, Ph.D., P.E. Submission Date: March 3, 2008

2 IMPROVING EXIT RAMP VISIBILITY IN WORK ZONES Cleveland State University 2121 Euclid Avenue, KB 1150 Cleveland, OH Principal Investigators: Stephen F. Duffy, Ph.D., P.E., F.ASCE Chairman and Professor, Civil & Environmental Engineering Director, University Transportation Center Cleveland State University 114 Stilwell Hall Cleveland, OH Deborah S. McAvoy, Ph.D., P.E., PTOE Assistant Professor Department of Civil Engineering Ohio University 119 Stocker Center Athens, OH Contractual Agreements: Elizabeth Cline Director of Sponsored Programs and Research Cleveland State University 2121 Euclid Avenue Parker Hannifin Building, 3 rd Floor Cleveland, OH Submission Date: March 3,

3 TABLE OF CONTENTS Page 1.0 STATEMENT OF THE PROBLEM BACKGROUND RESEARCH OBJECTIVES RESEARCH WORK PLAN BENEFITS OF THE PROPOSED RESEARCH ANTICIPATED RESEARCH RESULTS AND DELIVERABLES IMPLEMENTATION PLAN ITEMIZED BUDGET WORK TIME COST SCHEDULE REFERENCES...20 APPENDIX I BUDGET FORM...22 APPENDIX II FACILITIES...26 APPENDIX III QUALIFICATIONS OF THE RESEARCH TEAM...28 APPENDIX IV OTHER COMMITMENTS OF THE RESEARCH TEAM...34 LIST OF FIGURES Page Figure 1. Total and Injury Crashes at Exit Ramps in Ohio...4 Figure 2. Fatal Crashes at Exit Ramps in Ohio...4 Figure 3. Temporary Traffic Control for Work in the Vicinity of an Exit Ramp...7 Figure 4. Exit Ramp Drum Treatments...7 Figure 5. Comparative Parallel Evaluation Theory...10 Figure 6. Proposed Time Schedule...18 Figure 7. Work Time Cost Schedule...20 LIST OF TABLES Page Table 1. Speed Sample Size Requirements...13 Table 1. Simulator Speed Sample Size Requirements

4 1.0 STATEMENT OF THE PROBLEM In order to guide motorists through work zones in a safe and efficient manner, traffic control devices, such as temporary warning signs and channelizing devices, are used. In most work zones, numerous drums are utilized as channelizing devices to guide motorists through the work zone. The drums have alternating orange and white retroreflective stripes which make them highly visible, during daytime and nighttime driving conditions. The spacing of the drums are specified by the Federal Manual on Uniform Traffic Control Devices (MUTCD) and the Ohio Manual of Uniform Traffic Control Devices (OMUTCD). The manuals state the device spacing should be equal to twice the posted speed limit along tangent roadway sections and equal to the speed limit along taper roadway segments [1, 2]. At exit ramps, the standard is to delineate access to the exit ramp with channelizing devices and use guide signs to indicate that the exit is open to traffic. The guide sign is generally an exit sign mounted in the temporary gore at a height of seven feet from the pavement surface. While exit ramp locations along freeways only equate to approximately five percent of the total freeway mileage, the crashes associated with these locations account for higher proportions of 18 percent of all interstate crashes, 17 percent of injury crashes and 11 percent of fatal crashes. Over the past six years in the State of Ohio, approximately 14 fatal crashes and 1,166 injury crashes per year have occurred at or near exit ramps, as shown in Figures 1 and 2 [3]. The rationale behind higher crash frequencies at exit ramps is due to the complications associated with the driving task which involves merging, diverging and weaving traffic in combination with accelerating and decelerating vehicles. Further complicating the driving task is the introduction of construction work zones. Work zones along major freeways may extend for several miles with entrance and exit ramps included within the designated work zone. When entering the freeway, motorists are generally directed to merge with on-coming traffic and are channelized into the work zone. However, motorists attempting to exit the freeway find difficulties in determining the exact location or between which drums they should exit, particularly during nighttime driving conditions. Construction work zones have become increasingly familiar to motorists due to the rehabilitation and maintenance of the Nation s infrastructure. Unfortunately, most of the construction work zones require a lane reduction along the roadway in order to accommodate the construction activities, which create an unfamiliar environment for motorists resulting in traffic crashes. According to the Federal Highway Administration, the number of persons killed due to construction work zones in the past five years has increased by nearly eight percent with an average of 1,068 fatalities and more than 40,000 injuries per year [4]. In work zones, ramp-related crashes increase substantially, between 45 and 142 percent, as compared to non-construction periods [5]. 3

5 Total and Injury Crashes at Exit Ramps Total Crashes Injury Crashes Total Crashes Injury Crashes Figure 1. Total and Injury Crashes at Exit Ramps in Ohio Fatal Crashes at Exit Ramps Fatal Crashes Figure 2. Fatal Crashes at Exit Ramps in Ohio In order to reduce motorist confusion and enhance the visibility of exit ramps in work zones thereby decreasing work zone exit ramp-related crashes, the researchers propose to evaluate the effectiveness of various drum treatments at exit ramps in work zones with regard to the delineation and safety of the motorists. 2.0 BACKGROUND A preliminary literature review was performed to examine past research on alternative channelizing treatments for construction work zones. In order to identify past research results related to the proposed research, literature searches were conducted through Internet queries and traditional library resources. The topics covered in this proposal have not been previously submitted to ODOT or another agency for consideration. The concept that crash rates increase due to the presence of construction work zones has been evaluated by several researchers [6, 7, 8, 9, 10, 11, 12]. There has been little evidence indicating that construction work zones are safer or have fewer crashes than non-work zones. While performing a comparative study of crash rates at long-term urban freeway work zones, Rouphail et al. [5] found significant increases in crashes for long-term work zones. The 4

6 authors examined four long-term urban work zones between 1981 and To determine if the crash rates were statistically different between the period of construction and the two periods without construction (before and after periods), a Z-test was conducted with the null hypothesis stating that the crash rates were similar. The results of the Z-test found that ramp-related crash rates between the before, during and after periods were statistically significant at alpha equal to In other words, the ramp-related crash rates for the during period were significantly greater than the before and after periods. The rationale behind why construction work zones produce higher crash rates was examined by Li and Bai [13]. Li and Bai investigated how the concept of human factors impacts crash rates in work zones. Previous studies have indicated that 45 to 75 percent of all traffic crashes were caused by driver error [14]. The crash causation analysis led to the identifying human factors causes including following too closely, inattentive driving and misjudging the traffic conditions. Due to the crash-related risks associated with construction work zones, the crash potential for drivers can only be mitigated by preventing driver-related errors through the work zone. This can be accomplished with improved traffic control devices that are specifically aimed at providing positive guidance for all drivers through a work zone. Traffic control devices, specifically channelizing devices, are utilized to warn motorists of potential hazards created at the work zone and to guide the motorists safely past these hazards. Research by King and Luenfeld [15] shows the majority of the information needed for an accurate and timely path selection by the driver is acquired visually. Based upon the visual information received from channelizing devices such as drums, motorists can maneuver their vehicle appropriately and maintain a reasonable speed even through unusual and hazardous situations. In the NCHRP Report 236 by Pain et al. [16] published in 1981, research was conducted on the design and use of channelizing devices in terms of positive guidance through a work zone. Field experiments were conducted on highways with stationary long-term work zones with a posted speed limit of 55 miles per hour. The effectiveness of the various channelizing devices were examined with an instrumented automobile based upon device spacing, retroreflectivity and the presence of steady burn warning lights. NCHRP Report 236 concluded that steady burn warning lights do provide additional delineation to guide drivers through a work zone during nighttime driving conditions with the main advantage being the longer detection distance which promoted early lane changing behaviors. The authors recommended the use of steady burn warning lights at night particularly for taper sections, approach ends and curved roadways. Lafferty and Pennington [17] evaluated the effectiveness, in terms of positive guidance, of illumination devices on temporary concrete barrier walls in construction work zones for the Florida Department of Transportation in Four one-mile construction zones along I-75 were evaluated with three levels of illumination, including a temporary concrete barrier wall with warning lights, reflectors or without illumination devices. Vehicles were videotaped while driving through the work zone during daytime and nighttime driving conditions. The sections of the 5

7 temporary concrete barrier with lights were found to provide excellent guidance for motorists through the work zone. The recommendations of the authors were to maintain the use of warning lights on the temporary concrete barriers in work zones. The two previous studies indicate that the addition of steady-burn warning lights on drums near the exit ramp may provide sufficient guidance for motorists that are trying to locate the exit location. More recently, a project was initiated in July of 2007 by the Pennsylvania Department of Transportation to evaluate the use of non-standard colorized striped vertical panels at arterial exit locations [18]. The evaluation project will be completed in April of A preliminary presentation regarding the project was given at the Transportation Research Board in January of The non-standard color utilized for the vertical panels was fluorescent yellowgreen, which is traditionally utilized to identify pedestrian, bicycle or school-related activities. In addition to the vertical panels, drums are being evaluated for the arterial exit locations. The project evaluation is being conducted on a closed test track with posted speeds of 25 to 35 miles per hour with the main functional classification as an arterial. Several concerns were raised at the Transportation Research Board meeting regarding the color selection for the panels and drums in regards to the appropriateness for human factors and positive guidance. As the average age of motorists begins to increase, special attention should be given to the needs of the older motorists, particularly in construction work zones. Chiu et al. [19] studied the performance of 20 older drivers (over the age of 60) in construction work zones, as compared to 12 younger drivers (under the age of 35). Each subject drove through six construction work zone scenarios in a driving simulator showing drums, drums with reflectors and jersey barriers, while the lateral position and speed of the motorists were recorded. The analysis examined the average velocity, the number of times each driver got out of the driving lane and the amount of time they spent out of the lane. Overall, the younger motorists drove five to eight miles per hour faster than the older motorists. The drum and drum reflectors did not seem helpful to either group; however, the jersey barriers were favored by the older motorists. The reflectors were found to be extremely helpful to the older drivers through the work zone. These findings are similar to research conducted by Lyles et al [20]. The researchers found that older drivers require greater illumination in order to visualize objects clearly; however, they are impacted by glare more than younger drivers. Age-related visual deficiencies also include the diminished ability to recognize colors and traffic control devices. Therefore, visibility of the traffic control devices and the ability to recognize the need for decisions far in advance must be considered as the life expectancy of drivers continues to increase. 3.0 RESEARCH OBJECTIVES The objectives of this research will be to assess the effectiveness of various drums treatments at work zone exit ramps with regard to motorist safety and delineation. The evaluation of the effectiveness of the various drum treatments will be accomplished through a field and simulator experiment. In order to improve visibility of the exit ramp locations, it is anticipated that only two drums will be modified in the work zone. The remaining temporary 6

8 work zone signs and devices will not be altered from the specifications in the MUTCD and the OMUTCD. The drums that will be impacted include the drums prior to the exit ramp and the drum immediately following the exit ramp, as depicted in green in Figure 3. Figure 3. Temporary Traffic Control for Work in the Vicinity of an Exit Ramp The drum treatments that will be evaluated in this research include the following: 1. Orange drums with alternating green and white retro-reflective stripes. 2. Orange drums with alternating green and white retro-reflective strips with a steady-burn warning light. 3. Alternative option to be specified by the Ohio Department of Transportation (ODOT), if any. The various drum treatments are depicted in Figure 4. Facing Traffic 18" Facing Traffic 18" Facing Traffic 36 " 6" Reflectorized Sheeting (High-Intensity Grade) 36 " 6" Reflectorized Sheeting (High-Intensity Grade) 36 " 6" Reflectorized Sheeting (High-Intensity Grade) Figure 4. Exit Ramp Drum Treatments for Evaluation Motorist behavior through work zones depends upon the traffic control devices utilized and the motorist themselves in terms of their ability to recognize hazards, make proper decisions, control their vehicles and make evasive actions to avoid a hazard. These theories are based upon the concepts outlined in A User s Guide to Positive Guidance [21]. The positive guidance theories identify the key to successful motorist performance is efficient information 7

9 gathering and processing. When only given one task to perform at any given time, the information gathering and processing tasks are straightforward. However, as the number of task increases or the tasks become more complicated and then their ability to process the appropriate information in an adequate time period diminishes. On a daily basis, motorists encounter situations where there are overlapping informational needs presented in their driving environment. In order to fulfill these needs, motorists search the environment, detect information, receive and process it, make decisions, and perform control actions in a continual feedback process [21]. When motorists are faced with too many sources of information, they must select which piece of information they will process and which they will ignore. This leads to information overload, which can confuse motorists or cause them to miss important information. Such as is the case of construction work zones. In a work zone, the available width of pavement may result in a decreased number of lanes or reduced lane widths that create an unanticipated change in the motorists travel way. Motorists also find that shoulders, which prior to the construction functioned as a recovery area, may not be available. Other sources of confusion for the motorist include unfamiliar traffic control devices, a lack of visibility due to weather, lighting and deteriorated pavement markings. All of these factors lead to an increased demand on driver performance, while reducing the acceptable margin of error for their navigational functions. The rationale for the green retro-reflective tape on the drums is based upon the standard color scheme outlined in the MUTCD and OMUTCD as well as the general safety principles for construction work zones. The safety principles as stated in the MUTCD are to route road users through such zones using roadway geometrics, roadside features, and temporary traffic control devices as nearly as possible comparable to those for normal highway situations [1]. Green is designated as a guidance color and is typically utilized for the background of permanent signs along roadways, including freeways, such as exit signs. The development of sign color, shape, symbols and legends were based upon providing road users with simple, clear and meaningful instructions. Therefore, any modifications that are made to the current traffic control devices for improved motorist performance should be in accordance with the expectations of the road users. Since motorists are familiar with the green guidance signs along freeways, they should be able to relate the green stripes on the construction drums to the location of the exit ramp. Warning lights can be mounted on drums in work zones in order to increase nighttime visibility. The lights may be placed on drums or other channelizing devices used along, or in a cluster to warn drivers of a condition [1]. The steady-burn warning lights are most appropriate for use on channelizing devices, such as drums, in order to guide motorists through a work zone [1]. In the early 1990 s, ODOT removed the requirement for steady-burn warning lights on drums that were placed in a series in a work zone due to a research study s findings of their lack of effectiveness when compared with drums without the steady-burn warning lights [22, 23]. For this research, the steady-burn warning lights will only be considered for two drums at the exit ramp, as shown in the previous Figure 3, in order to assist motorists in locating the exact location of the exit ramp. 8

10 4.0 RESEARCH WORK PLAN The following tasks will be performed in order to fulfill the research objectives of determining the effectiveness of various drum treatments to enhance exit ramp visibility. Task 1: Conduct a Literature Review A literature review will be performed to examine past research on work zone crashes, particularly those associated with exit ramps, and alternative devices in work zones including their application and effectiveness of their use as well as other related topics. In order to identify past results related to the proposed research, literature searches will be conducted through Internet queries and traditional library resources. All materials will be critically reviewed for their objectives, target audience, data and analysis tools, performance measures, evaluation methodology and results, safety and mobility impacts, use of innovative technology and conclusions. Task 2: Investigate Exit Ramp Crash Trends Exit ramp crashes in work zones will be examined for the past five years in the State of Ohio to determine the extent of the crashes that are associated with motorist confusion regarding the location of the exit ramp in a work zone area. It should be cautioned however, that crash trends in work zones may not be fully attributable to motorist confusion in regards to the location of the exit ramp. Other factors should also be considered in order to draw meaningful conclusions, such as the number of construction days, the weather conditions, the condition of the road surface, etc. The reserachers will work with ODOT personnel to identify past work zones along freeways in the State of Ohio in order to focus the crash trend investigation on specific roadways during particular months. In addition to the crash data and trends, the historical traffic volume data, roadway geometry and other factors will be gathered for inclusion in the analysis. The traffic crash trends will quantify the past crash experience associated with exit ramps along freeways in work zones. Traffic crash rates will then be determined using the historical traffic volume data in order to account for exposure during the construction period. Roadway geometry data, including lane widths, type of road closure, horizontal and vertical curvature and presence or absence of a deceleration lane will be collected at all of the past construction sites through examination of construction drawings and discussions with ODOT engineers. Task 3: Conduct a Field Experiment of Driver Behavior The purpose of this research is to determine the effectiveness of various drum treatments at work zone exit ramps as compared to typical drum treatments through a field experiment. Site Selection Construction projects scheduled during the summer and fall of 2008 on freeways under ODOT jurisdiction and approved by ODOT will be selected for evaluation. Great Lakes Construction Company, a member of the University Transportation Center s Advisory Board, has agreed to include any of their construction projects in the selection process. In order to properly address the research objective, it is proposed that the sites selected represent 9

11 a variety of geographic, environmental, and traffic conditions. This will include the selection of sites in rural and urban areas with low and high traffic volume conditions. If adequate field sites cannot be identified, the service roadways of US-23 in Delaware County may be utilized as a test-track with a simulated work zone, if so approved by ODOT. If the US-23 service roadways are utilized, the establishment of the work zone will be designed by the researchers, approved by ODOT representatives and erected. The temporary traffic control devices will be purchased for this research project through Plastic Safety Systems, which also holds a seat on the CSU Transportation Advisory Board.. A comparative parallel evaluation will be conducted for this research comparing the measures of effectiveness for a group of control sites verses a group of test sites. A test site will be a work zone where the various drum treatments will be utilized at an exit ramp, whereas, a control site will be a location where typical drums with orange and white alternating retro-reflective stripes will be used at an exit ramp. The comparative parallel evaluation assumes that motorist in the test and control sites would perform similarly if the alternative drum treatments were not utilized at the test sites. The difference in the measures of effectiveness between the test and control groups can then be attributable to the alternative exit ramp drums utilized at the test sites. A schematic drawing depicting the theory of the Comparative Parallel Evaluation Plan is shown in Figure 5. Legend Test Group MOE Control Group MOE Expected Test Group MOE Measure of Effectiveness (MOE) Change in MOE Before Period After Period Time Figure 5. Comparative Parallel Evaluation Theory Data Collection Traffic operational, safety and motorist compliance data will be collected for each site. The measures of effectiveness for the field experiment will be as follows: Traffic crash data, Speed approaching the exit ramp, Lateral placement of vehicles, and Motorist determination of exit ramp location (for US-23 field experiment only). 10

12 Traffic Crash Data To assess safety characteristics at sites, traffic crash data will be collected from the Ohio Department of Public Safety for each site. The dates and locations of the traffic crashes will be analyzed in order to determine where the crash occurred during the work zone and whether or not driver confusion with the location of the exit ramp could be the cause of the crash. Therefore, the crash analysis will concentrate upon those crashes related to delineation within the work zone. Positive guidance for motorists through the construction zone will be deemed more critical during nighttime driving conditions due to the reduced visibility of the freeway and the exit ramp. As such, all crashes will be separated into daytime and nighttime crashes for each site. It is anticipated that the number of traffic crashes will be extremely low. This is due to the fact that traffic crashes, in general, are rare events. Compounded by the temporary nature of work zones and the relatively short duration of highway projects, it is expected that the crash frequency would be further reduced from what is normally observed along non-work zone roadways. Speed Data Speed data will be collected for vehicles traveling through the work zone using a portable radar detector. The speed data will be collected at several locations in the work zone approaching the exit ramp where a safe location for speed measurements is available. In general the speed data will be collected prior to the notification of the upcoming exit (greater than 1 mile in advance of the exit ramp), half the distance between the notification of the upcoming exit and the exit ramp (approximately 0.5 miles in advance of the exit ramp), 1000-feet in advance of the exit ramp, 500-feet in advance of the exit ramp, 250-feet in advance of the exit ramp, 100-feet in advance of the exit ramp and at the exit ramp. The speed data will be collected and analyzed separately during the daytime driving conditions and the nighttime driving conditions. The speed data will only be collected during off-peak periods when motorists are able to travel at their desired speed, unaffected by congestion, typically experienced during peak periods. The analysis of the speed data will be used as an indication of a motorist s perceived risk while approaching an exit ramp in a work zone. The speed data for each site will be analyzed for each observation location including the calculation of the mean speed and the corresponding standard deviation. If the various construction sites have differing speed limits, the mean speed deviation variable (speed limit observed speed) will be used as a surrogate for mean speed. Lateral Placement Data Driver behavior and vehicle placement of vehicles traveling through the work zone will be recorded using video cameras for various construction sites where the motorists are unaware they are being observed or through the use of an instrumented vehicle in the case of the US-23 site. A digital video camera will be mounted inside a survey vehicle and data will be recorded through the approach to the exit ramp in the work zone while following a target vehicle in the traffic stream. With this approach, motorists will not be aware they are being monitored and thus, their driving behavior will be unbiased. 11

13 The lateral placement data will then be analyzed in the laboratory in order to obtain quantifiable lateral placement data for each observed vehicle. The lateral placement of a vehicle will be based upon the location in the lane with respect to the centerline of the vehicle. The lateral placement of vehicles through the work zone will be quantified in order to assess the ability of the motorist to detect the exit ramp while traveling through the work zone. Lateral placement data that exhibits extreme variations in regards to the centerline of the lane in the vicinity of the exit ramp may be due to driver confusion or inability to visualize the location of the exit ramp. Motorists that exhibit extreme variations prior to the vicinity of the exit ramp will be further examined for deviations in lateral placement throughout the work zone. Motorist Determination of Exit Ramp If the US-23 site is utilized for a portion of the experiment, motorists will be asked to identify the first moment that they are able to visualize the exit, the moment that they are absolutely confident of the exact location of the exit, and will be asked to exit at the location they deem is appropriate. This information will be utilized to assess the ability of the various drum treatments to warn participants of an approaching exit ramp and guide them to the proper location. The motorists will be informed that there is an exit ramp ahead that they need to utilize; however, the motorists will not be informed of how the exit ramp is delineated. The effectiveness of the various drum treatments will be based upon when the motorists can appropriately visualize the exit and safety conduct the maneuver. After the driving portion of the experiment, each motorist will be asked to fill out a questionnaire documenting their demographic information in order to determine the representative nature of the participants as well as questions related to the work zone, such as what the differences were between the various scenarios. The motorists will be randomly assigned to alternating drum treatments in order to equally expose motorists to each drum treatment. Sample Size Determination In order to determine the number of sample motorists required to assure a statistically valid representative sample, the following formula will be considered in the estimation of the sample size [24]: Where: Z b = critical value corresponding to a given value of b in the upper tail of the standard normal distribution Z a = critical value corresponding to a given value of a/2 in the lower and upper tail of the standard normal distribution s = standard deviation of the difference e = detectable difference in the means 12

14 Various sample size requirements based upon previous studies conducted by the researcher were calculated. The level of confidence was selected at 95 percent or alpha equal to 0.05 and the power was selected at 80 percent or beta equal to Table 1 outlines the required speed sample sizes based upon varying standard deviations and detectable speed differences. Table 1. Speed Sample Size Requirements Standard Deviation Number of Vehicles Detectable Difference in Mean Speed 5 mph 4 mph 3 mph 2 mph 1 mph With a high variation in speeds at one site, attempting to detect a one mile per hour difference in mean speeds, even at the same site, should result in a statistically significant test often. Therefore, as the standard deviation increases, so should the detectable difference. Therefore, a detectable difference of two miles per hour in mean speeds will be selected as the basis for this research. A target sample of 100 speed observations would maintain a power of 80 percent and a level of confidence of 95 percent. Task 4: Conduct a Controlled Laboratory Experiment The purpose of this research is to determine the effectiveness of various drum treatments at work zone exit ramps as compared to typical drum treatments in a controlled laboratory setting. The validity of the driving simulator will be determined based upon comparisons between the field experiment data and the simulator experiment data. If the driving simulator validity can be verified, the driving simulator can be utilized to determine the effectiveness of other traffic control devices for similar situations. If the validity cannot be verified, the findings can assist future research experimental designs. The simulator will be used to conduct an experiment of driver performance in highway work zones with various drum treatments at exit ramps. The driving simulator used for the controlled laboratory experiment is owned by the University Transportation Center at Cleveland State University, the DriveSafety DS-600c Research Simulator. The simulator is a fully integrated simulator with a 180-degree display approximately nine-feet in height, a vehicle motion simulation platform and a full-width automobile cab including a windshield, driver and passenger seats, center console, dash and instrumentation. The simulation software provides for a realistic driving experience with simulated vehicle dynamics, traffic conditions, and environmental conditions. The researcher will work with computer programmers and technicians at Cleveland State University to customize a program simulating a work zone with the various drum treatments at work zone exit ramps. The simulated driving environment will be designed to replicate the temporary traffic control conditions present in the field experiment. 13

15 Simulator Experiment Procedure A detailed test procedure/sequence will be developed with standard instructions for each participant of the simulator experiment. The participant will be first orientated to the simulator and the location of the controls followed by a brief introduction to the purpose of the simulator experiment. The participants will be informed that the experiment test the effects of various traffic control devices on driver behavior and performance while driving through a freeway work zone. They will be instructed to drive through the scenarios as if they were traveling to or from work or school, driving at a speed appropriate for the conditions presented during the scenario and exit the freeway at the first available location. To reduce the bias associated with the simulator experiment, the participants will be equally exposed to an initial scenario in equal proportions. Data Collection Traffic operational, safety and motorist compliance data will be collected for each simulator scenario. The measures of effectiveness for the laboratory experiment will be as follows: Traffic crash data, Speed approaching the exit ramp Lateral placement of vehicles, and Motorist determination of exit ramp location. The performance of the motorists will be recorded on the control station of the simulator as well as with a video camera for comprehensive data extraction and analysis without the participant present. The data collection procedures for the simulator experiment will be similar to those previously described for the field experiment. Sample Size Determination In order to determine the number of participants required to assure a statistically valid representative sample, the same methodology utilized for the field experiment will be utilized based upon standard deviations from previous simulator studies conducted by the researcher. The level of confidence was selected at 95 percent or alpha equal to 0.05 and the power was selected at 80 percent or beta equal to Table 2 outlines the required speed sample sizes based upon varying standard deviations and detectable speed differences. Table 2. Simulator Speed Sample Size Requirements Standard Deviation Number of Vehicles Detectable Difference in Mean Speed 5 mph 4 mph 3 mph 2 mph

16 For the field experiment, the detectable difference in mean speed was selected as two miles per hour. However, due to time constraints, resources and difficulties in obtaining large samples with past research studies, a detectable difference in mean speeds for the simulator study was selected at three miles per hour. A target sample of 100 participants would maintain a power of 80 percent and a level of confidence of 95 percent at a detectable difference in mean speed of three mph. Focus Group Selection The focus group of drivers will be composed of a sample from the general driver population of Ohio, selected from residents of metropolitan Cleveland, and with experience in driving on the region s freeway system on their commute to work or to school. The focus group will be selected such that they are considered representative of the general driver population in the State of Ohio. Due to the participation of human subjects in this research, federal regulations require a review and approval for the proposed research methodology by an Institution Review Board (IRB). For the research conducted in this experiment, both the Ohio University and Cleveland State University IRB will approve the research methodology detailing the procedures for the simulator experiment, the recruitment script, the research informed consent form and the driver participation survey form prior to the commencement of the experimental portions of the research. The participants will be solicited on a voluntary basis by the researcher through direct person to person contact or by . Each individual will be informed that their participation is voluntary and they will not be compensated or penalized for their decision. Purposive sampling will then be utilized to supplement the convenience sampling based upon age or gender distribution of the sample in general comparison to the population in Ohio. Task 5: Determine the Relative Effectiveness of the Various Drum Treatments for Exit Ramps The statistical significance of the effectiveness of the drum treatments will be tested to determine whether the changes observed in the measures of effectiveness of crash frequency, speed, lateral placement and motorist perception were attributable to the alternative drum treatment or to chance. The statistical test that will be utilized to determine the effectiveness of the drum treatments for the field and simulator experiments will be the one-way analysis of variance (ANOVA). To perform the ANOVA, an F-statistic is calculated which is equal to the mean squares between the groups divided by the mean squares within the groups. If F-calculated is greater than F-critical obtained in available statistical tables, the difference in the means will be statistically significant. Otherwise, the difference in the means will not be statistically significant. Based upon the participants selected for the focus group, a paired t-test may be conducted when the participants of the experiment are nearly similar. In the paired t-test, a paired t-statistic is calculated based upon the sample mean and standard deviations then compared with a critical paired t-statistic obtained in available statistical tables. If the calculated statistic is greater than the critical statistic, the difference in means is statistically significant. 15

17 Statistical tests will also be conducted to determine the validity of the driving simulator in terms of comparable results to the field experiment. Blaauw [25] described methods to validate the use of driving simulators for behavioral research with absolute and relative validity procedures. In 2001, Godley [26] further refined Blaauw s methods to include interactive relative validity. Absolute validity will be confirmed if the means of the performance measures for the field experiment and simulator experiment are statistically similar. Relative validity will be confirmed if the differences in the experiments means are similar in magnitude and direction. Interactive relative validity will be confirmed if the experiments means are statistically similar in terms of general trends. Task 6: Prepare a Final Report A final report will be prepared detailing all of the activities performed as a part of this research, as well as the results and recommendations for the use of alternative drums treatments in work zones at exit ramp locations. The progress of the project will be reported to ODOT s Technical Liaison as well as through interim progress reports submitted on a quarterly basis throughout the duration of the project. 5.0 BENEFITS OF THE PROPOSED RESEARCH With the continued roadway reconstruction efforts throughout the nation, work zone safety has been a priority for traffic engineers and road agencies. Efforts to reduce congestions during the construction period have increased the amount of construction work that occurs during the nighttime hours. Even when construction is not occurring during the nighttime hours, the work zone delineation is maintained during the duration of the reconstruction of the roadway, which can continue for several months or an entire construction season. Construction zones create additional hazards for motorists as a result of the unfamiliar roadway environment that is created by the work zone. Without the occurrence of a work zone, crashes occurring near exit ramps along interstates occur at a much higher proportion than other types of crashes. The burden on motorists to perform at exit ramps is much greater than at other locations along the freeway due to merging, diverging, and weaving maneuvers, as well as accelerating and decelerating vehicles. The presence of construction work zones only complicate the processing requirements of the motorist at an exit ramp where the exact location of the ramp is difficult to locate among the numerous drums channelizing the traffic away from the closed portion of the roadway. The research presented will examine the effectiveness of various drum treatments in work zones at exit ramps in order to reduce crashes with a low-cost treatment. The results from this research will be applicable across the nation. The analysis of the field and driving simulator studies will also examine motorist behavior in the vicinity of exit ramps in order to facilitate future discussions regarding motorist behavior without the presence of a work zone in order to further reduce crashes along freeways. In addition, as the average age of motorists begins to increase vastly due to the numbers of children born during the baby-boomer generation, the visibility and recognition requirements of the driving public will also begin to increase. 16

18 Due to the increased demand on traffic control devices to guide motorists safely along the roadways, improvements to the positive guidance theories and work zone layouts must be considered in order to limit the number of crashes along the roadways. The Federal Highway Administration has funded several research studies to determine the effectiveness of various channelizing devices. Most of the research has been performed with instrumented vehicles on vacated or low volume roadways for the safety of the motorists participating in the research. As a result of the difficult field data collection efforts due to the safety issues related to human subjects, driving simulators have emerged as an alternative methods that allows experimental control, efficiency, low cost and ease of data collection. However, the question of validity of driving simulators as useful human factor research tool must be answered. This research will attempt to validate the driving simulator at Cleveland State University so that various traffic control devices in work zones can be examined without the cost and safety concerns associated with a field study. As this research is aimed at improving positive guidance for motorists through work zones, the validated driving simulator can be used in the future to examine the behaviors of older drivers as compared to younger drivers through work zones in an attempt to improve visibility and recognition of traffic control devices in a work zone. 6.0 ANTICIPATED RESEARCH RESULTS AND DELIVERABLES It is anticipated that the results of the field and simulator experiments conducted in this research will identify alternative positive guidance techniques in the form of alternative drum treatments at exit ramps located in work zone areas which will reduce the crash potential for motorists traveling along freeways. The selected alternative drum treatments have been chosen for their cost effectiveness. The intent is not to increase the cost burden on ODOT or the contractor, but to provide a low-cost solution that will lead to a cost savings for ODOT, time savings for the contractor and substantial savings to society with the reduction in crashes. Therefore, the drum treatments selected will require little, if any, additional cost to any construction project. The resulting deliverables of this research will be as follows: The research will attend a project start-up meeting at ODOT to discuss the contractual obligations, scope of the work, the deliverables and project schedule. Synthesis of the literature review List of selected test and control sites Preliminary data summaries and findings Summary of driving performances of the focus group from the controlled laboratory experiment and population of the field experiment Final project report describing all activities conducted as a part of this research, results and recommendations. The report will provide the results of the effectiveness evaluation and statistical analysis. One original and five copies of the draft final report and draft executive summary will be submitted to ODOT for review at the end of the twelfth month in the sixteen-month project period. Four 17

19 months are included in the project schedule for review of the final draft report by ODOT staff. Upon receiving the comments from ODOT, the report will be finalized with 65 copies of the report and 220 color copies of the executive summary submitted by the contract completion date. Electronic versions of the final report and executive summary will also be submitted. Quarterly progress reports detailing project status to date, including summaries of the data collection and analysis. The quarterly progress reports will clearly describe the work performed during that quarter and the work that is expected to occur in the next quarter. Any constraints impacting the completion of the work will also be documented in the quarterly progress reports. Each quarterly report will also contain a financial report. A Research and Development Newsletter Article will be developed and submitted to ODOT for review and inclusion in the Research and Development Newsletter. The researchers will participate in a Project Review Session and a Project Wrap-up Meeting with ODOT to discuss the results of the research. The proposed time schedule including the estimated time needed to complete each task, as well as the proposed deliverables for completing the project, are shown in Figure 6. Figure 6. Proposed Time Schedule 18

20 7.0 IMPLEMENTATION PLAN If the results of the research indicate that alternative drum treatments at exit ramps in work zones can reduce crash frequency and improve motorist maneuverability and recognition of the exit ramp, the research results will be promoted to a wide audience of traffic engineers, road agencies and construction companies. The goal of the University Transportation Center at Cleveland State University is improving work zone safety and mobility. The Federal Highway Administration participates in the activities of the University Transportation Center and will be a natural conduit for dissemination of the results of this research. In addition to the Federal Highway Administration and ODOT, the results of this research will be submitted to the Transportation Research Board for publication and presentation at the Annual Meeting in January of Secondary research results, such as the evaluation of older driver abilities, will support various organizations, such as the AAA Foundation for Traffic Safety, the National Highway Traffic Safety Administration and metropolitan planning organizations, in their efforts to enhance elderly mobility. Additional safety or traffic control device evaluations can be performed with the validated driving simulator through the University Transportation Center at Cleveland State University. The use of the simulator will remove safety concerns associated with a field experiment conducted with human subjects. The driving simulator will be a costeffective method for evaluating potential modifications to traffic control devices without having to absorb the cost associated with physically manufacturing the devices under evaluation. 8.0 ITEMIZED BUDGET The proposed budget for this project is $149,985. The itemized budget for the project is provided on the following pages. The partnering agency, Cleveland State University s University Transportation Center, will contribute 50 percent of the funds for the project. 9.0 WORK TIME COST SCHEDULE The proposed research project activities will be conducted through Cleveland State and Ohio Universities. Details regarding the facilities that will be utilized for this research project are provided in Appendix II while the qualifications and resumes of the research team are provided in Appendix III. The other commitments of the research team are provided in Appendix IV detailing the commitments to the success of this project both Universities. The letter of commitment with Ohio University is also included in Appendix IV. It is estimated that the draft final report will be completed in 12 months with an additional four months for the review, approval and resubmission of the final report. Therefore, the project contract length is estimated at 16 months. The detailed breakdown for the hours and cost by task are provided in Figure 7. 19

21 Project Title: Improving Exit Ramp Visibility in Work Zones Labor Costs are computed at a per hour of: (insert amount in cell J2) TASKS $26.31 TOTAL TASK HOURS TOTAL LABOR COSTS MONTH $2, $5, $60, $52, $21, $7, *Includes Report 0 $ Modification 0 $ in Months 0 $ $0.00 Monthly Hours Monthly Labor Costs $4, $3, $21, $31, $23, $13, $13, $13, $7, $5, $9, $3, $149, Quarterly Reports X X X Draft Final Report X Final Report X in Month 16 Insert "X" to denote submission of above reports. Figure 7. Work Time Schedule 10.0 REFERENCES 1. Manual on Uniform Traffic Control Devices, 2003 Edition. U.S. Department of Transportation, Federal Highway Administration, Washington D.C. 2. Ohio Manual of Uniform Traffic Control Devices, 2003 Edition. Ohio Department of Transportation, Columbus, Ohio. 3. Ohio Traffic Crash Facts, 2001 through 2006 Editions. Ohio Department of Public Safety, Columbus, Ohio. 4. Facts and Statistics. Work Zone Mobility and Safety Program, Office of Operations, Federal Highway Administration Rouphail, N.M., Yang, S., and Fazio, J. Comparative Study of Short- and Long-Term Urban Freeway Work Zones. Transportation Research Record 1163, Garber, N.J. and Zhao, M. (2002) Crash Characteristics at Work Zones. Research Report VTRC 02- R12. Virginia Transportation Research Council, Virginia. 7. AASHTO. (1987) Summary Report on Work Zone Crashes. American Association of State Highway and Transportation Officials, Washington D.C. 8. Ullman, G.L. and Krammers, R.A. (1990) Analysis of Crashes at Long-Term Construction Projects in Texas. Report FHWA/TX-90/1108-2, Washington D.C. 9. Graham, J. L., R.J. Paulsen, and J.C. Glennon. (1978). "Accident Analysis of Highway Construction Zones." Transportation Research Board, National Research Council, Washington, D.C. 10. Ha, Tae-Jun and Nemeth, Z.A. (1995). "Detailed Study of Accident Experience in Construction and Maintenance Zones." Transportation Research Record 1509, Wang, J., Hughes, W. E., Council, F. M., and Paniati, J. F. Investigation of Highway Work Zone Crashes: What We Know and What We Don t Know. Transportation Research Record 1529, Khattak, A. J., Khattak, Aemal J., and Council, F. M. (2000). "Effects of Work Zone Presence on Injury and Non-injury Crashes." Accident Analysis and Prevention 34, 34,

22 13. Li, Y. and Bai, Y. (2007). Investigating the Human Factors Involved in Severe Crashes in Highway Work Zones. Proceedings of the 2007 Mid-Continent Transportation Research Symposium, Ames, Iowa. 14. Wierwille, W.W., Hanowski, R.J., Hankey, J.M., Kieliszewski, C.A., Lee, S.E., Medina, A., Keisler, A.S., and Dingus, T.A. (2002) Identification of Driver Errors: Overview and Recommendations. Report FHWA-RD , McLean, Virginia. 15. King, G. F. and M. Lunenfeld. (1971). "Development of Information Requirements and Transmission Techniques for Highway Users." Washington D.C. 16. Pain, R. F., McGee, H.W., and Knapp, B.G. (1981). "Evaluation of Traffic Controls For Work Zones." Transportation Research Board, Washington, D.C. 17. Lafferty, A. and Pennington, J. (1995). "Type "C" Steady Burn Warning Lights on Temporary Concrete Barrier Wall in Active Work Zones." Florida Department of Transportation, Office of Construction/Product Evaluation. 18. Transportation Research Board, Research in Progress. Evaluation of Striped Vertical Panels in Temporary Traffic Control Zones Chiu, S. A., R.R Mourant, A. Belambe, and B.K. Jaeger. (1997). "A Study of Nighttime Highway Lane Shifts." Northeastern University, Boston, Massachusetts. 20. Lyles, R.W, Kane, M.R., Vanosdall, F. and McKelvey, F.X. (1997). Improved Traffic Control Device Design and Placement to Aid the Older Driver, Final Report. NCHRP. 21. A User s Guide to Positive Guidance. U.S. Department of Transportation, Federal Highway Administration, Pant, P.D., and Park, Y. "Effectiveness of Steady burn warning lights for Traffic Control in Tangent Sections of Highway Work Zones." Transportation Research Board, National Research Council, Washington, D.C. 23. Pant, P. D., Huang, X. H., and Krishnamurthy, S. A. (1991). "Steady burn warning lights in Highway Work Zones: Further Results of Study in Ohio." University of Cincinnati, Department of Civil and Environmental Engineering. Cincinnati, OH. 24. Accident Research Manual. (1980). Federal Highway Administration RD , February, 1980, Federal Highway Administration, United States Department of Transportation, Washington, D.C. 25. Blaauw, G. J. (1982). "Driving Experience and Task Demands in Simulator and Instrumented Car: A Validation Study." Human Factors 24, Godley, S. T., Triggs, T. J., and Fildes, B. N. (2001). "Driving Simulator Validation for Speed Research." Accident Analysis and Prevention 34, April 2001, 34,

23 APPENDIX I BUDGET FORM 22

24 Project Title: Proposing Agency: Principal Investigator: Co-Principal Investigator(s) Improving Exit Ramp Visibilty In Work Zones Cleveland State University Stephen F. Duffy, Ph.D., P.E. Total Funding Contribution: $ 74, Partnering Agency: Principal Investigator: Co-Principal Investigator(s) Total Funding Contribution: (Duplicate the section on partnering agency as needed so that one section is provided for each partner.) ODOT Funding Proposing Agency Matching Funds Partnering Agencies Total Project Cost SALARIES & WAGES Specify number of hours to be work and hourly rate for each individual below. Salaries & Wages may be shown as a percentage of a total salary. In this case, the percentage of the salary to be paid and the total salary for each individual must be listed. The same unit, hours or percent, must be used for all personnel in all sections of the final proposal budget form. For example: PI: Doug Smith (120 $64.05/hour) $7, $0.00 $0.00 $7, PI Stephen Duffy $1, $15, $16, Co-PI (Name) Student(s)/Intern(s) 2 Students $0.00 $8, $15, $23, Technicians (Name) Others (Secify Role & Name) SUB-TOTAL SALARY & WAGES $0.00 $0.00 $9, $30, $0.00 $39, FRINGE BENEFITS Provide an explanation of what is included and how the figure was derived for each personnel category (e.g.: 15% of Salary & Wages). PI $ $2, see above $3, Co-PI Students/Interns Technicians Others (Specify) SUB-TOTAL FRINGE BENEFITS SUB-TOTAL SALARY & WAGES AND FRINGE BENEFITS $0.00 see above $0.00 $0.00 $0.00 $ $2, $0.00 $3, $9, $32, $0.00 $42,

25 SUBCONTRACTOR A copy of the subcontractor s budget must be attached. Reimbursement to Contractor for Subcontractor performance is subject to state accounting guidelines as is the Contractor. SUB-TOTAL SUBCONTRACTOR $62, $34, $96, TRAVEL Must be in accordance with current state guidelines. Available on-line at In-State Travel $0.00 (Destination within Ohio) Provide destination, purpose, total mileage, total # of days, total # of meals, total # of trips, names of individual(s) traveling. Out-of-State Travel (Destination outside Ohio) Provide destination, purpose, total mileage, total # of days, total # of meals, total # of trips, names of individual(s) traveling. SUB-TOTAL TRAVEL $0.00 $2, $2, $0.00 $2, $2, SUPPLIES Provide details if over 5% of total budget. SUB-TOTAL SUPPLIES $0.00 EQUIPMENT At least 2 quotes for each piece of equipment must be attached. (See equipment policy - Section for details and exceptions.) List all items separately. Time at which the purchase shall be made must be stated (e.g.: at project initiation, within first five months, etc.) SUB-TOTAL EQUIPMENT $0.00 PRINTING Provide a breakdown of charges including, charge per page, # of pages, total # of copies, binding charges, etc.) Quarterly Reports $0.00 Interim Reports $0.00 (if applicable) Draft Final Report $0.00 Executive Summary $0.00 Final Report $0.00 SUB-TOTAL PRINTING $0.00 $0.00 $0.00 $

26 IN-DIRECT COSTS Limited to 35% of Salaries & Wages for Universities $3, $5, INCLUDE IN ABOVE_NEED UPDATE $8, FEES For Commercial Organizations Only. Negotiated amount based on % of direct costs (excluding sub-contractor and equipment) SUB-TOTAL INDIRECT COSTS AND FEES $0.00 $3, $5, $0.00 $8, OTHER EXPENSES Any project expense which does not fall into another category. Provide detailed explanation of the expense and applicable breakdown of costs. List individually by category. SUB-TOTAL OTHER EXPENSES $0.00 TOTAL PROJECT COST $74, $74, $0.00 $149,

27 26

28 27

29 2608 Great Lakes Way Hinckley, Ohio Phone: Fax: February 27, 2008 Attn: George Palko President The Great Lakes Construction Co., Inc 2608 Great Lakes Way Hinckley, OH Gentlemen: As per your request, Cleveland Barricading Systems (CBS) details pricing below to set up the proposed Work Zone in Delaware County at an exit ramp along US-23. It is our understanding that the standard drums and the special drums will be furnished by Plastic Safety Systems. The Work Zone signs, sign stands or No. 3 Posts, and Type A Lights are to be furnished by CBS. At the completion of the project, CBS will return to the site to remove all of the equipment. All work is to comply with the latest edition of the OMUTCD. It is anticipated that the Work Zone duration would be six months. Lump Sum Price $2, Please advise if you require any additional information or have any questions regarding this proposal. Sincerely, CLEVELAND BARRICADING SYSTEMS K. Leonard More General Manager 28