FLORIDA S RETURN ON INVESTMENT FROM PAVEMENT RESEARCH & DEVELOPMENT

Transcription

1 FLORIDA S RETURN ON INVESTMENT FROM PAVEMENT RESEARCH & DEVELOPMENT Corresponding Author Wiley Cunagin, PE, PhD Atkins 3700 Capital Circle SE Apt. 415 Tallahassee, FL Phone: wcunagin@gmail.com James Musselman, PE State Bituminous Materials Engineer Florida Department of Transportation State Materials Office 5007 Northeast 39th Avenue Gainesville, FL Jim.Musselman@dot.state.fl.us Rhonda Taylor, PE Florida Department of Transportation State Pavement Design Engineer Pavement Management Section Office of Design 605 Suwannee Street Tallahassee, FL Rhonda.Taylor@dot.state.fl.us Bruce Dietrich, PE Pavement Analytics LLC PO Box 670 Tallahassee, FL Phone: bdietrich@pavementanalytics.com Text 5,237 Tables and Figures 2,000 Total 7,237

2 ABSTRACT The Florida Department of Transportation (FDOT) has recently implemented an innovative pavement management forecasting methodology. This process is called Florida s Analysis System for Targets (FAST). FAST uses bottom-up, section level forecasts to develop regional and system wide network pavement condition forecasts and evaluates the effects of alternative resurfacing funding scenarios. FAST is calibrated and validated annually using the latest section level pavement condition data. This provides the ability to assess the latest impacts of changes in pavement materials, processes, and construction methods and management. The FAST system allows FDOT to leverage its extensive pavement management database to address the issue of funding limitations by ensuring that transportation dollars are efficiently allocated to provide a safe and comfortable riding experience to the roadway traveler. FAST provides FDOT engineers and managers the ability to better predict the future condition of its highway system in a manner that allows managers to establish the level of funding necessary to cope with projected resurfacing needs over a given planning period. The FDOT has been engaged for the past two decades in an initiative to improve the durability of its pavement sections. Using the FAST system, Florida s experience has shown that there is an excellent return on investment for research and development into pavement materials, processes, construction methods and management, and pavement management technology. Based on the adoption of Superpave, changes to open graded friction courses, changes to FDOT s Construction Quality Control Program as well as a consistent resurfacing program, Florida s pavements are lasting longer and FDOT management is now able to reallocate resources that would have been programmed for resurfacing to providing much needed new capacity. This tool has enabled FDOT to confidently reduce its resurfacing program and reallocate to capacity projects approximately $3 billion in non-essential resurfacing funds over the next ten years. INTRODUCTION The Florida Department of Transportation (FDOT) has recently implemented an innovative pavement management forecasting methodology. This process is called Florida s Analysis System for Targets (FAST). FAST uses bottom-up, section level forecasts to develop regional and system wide network pavement condition forecasts and evaluates the effects of alternative resurfacing funding scenarios. The FDOT has been engaged for the past two decades in an initiative to improve the durability of its pavement sections. This effort has addressed materials research, pavement management technology, and construction methods and management. The materials research component has included both structural layer and friction course improvements. This annually calibrated, section level detail provided by FAST allows the effects of these initiatives to be directly quantified for the future.

3 This tool has enabled FDOT to confidently reduce its resurfacing program and reallocate to capacity projects approximately $3 billion in non-essential resurfacing funds over the next ten years. PAVEMENT DESIGN AND MATERIALS BACKGROUND Structural Courses Throughout its history, FDOT has used a wide variety of asphalt materials in the construction of its pavements, ranging from (in the early days) surface treatments to sand bituminous road mixes to more specialized materials, such as Amulithic Asphaltic Concrete and Macasphalt Binder Courses (1). As asphalt technology advanced nationally, it also advanced in Florida. By the 1960 s, typical asphalt mix types used in Florida included Type I & Type II surface courses, Type III leveling courses and a standard binder course. At that time, FDOT used the Hubbard-Field method to design fine sized sand mixes, but coarser mixes were designed primarily based on a range of gradation requirements, experience in the field and visual methods (2). In 1970 FDOT converted to the Marshall Mix design method and correspondingly changed the types of mixes routinely placed. By the mid 1980 s, the typical mixes used in Florida (3) were as follows: Base Mixes: ABC-1, ABC-2, ABC-3 Leveling Mixes: Sand Asphalt Hot Mix (SAHM), Type-II, Type-III Structural Mixes: S-I, S-II, S-III Friction Mixes: FC-1, FC-2, FC-4 In the early 1980 s, FDOT also adopted a milling and resurfacing program, where old pavements were milled and the recycled. In addition to conserving resources and reducing costs through recycling, the milling operations frequently removed substandard materials from the pavement structure and reduced the likelihood of reflective cracking and/or rutting due to an underlying layer. While these newer mixes and the Marshall Design methodology represented an improvement over the older generation of Hubbard-Field asphalt mixes, they still had some significant shortcomings. Due to the relative softness of native Florida limestone, mixes were designed with the 50 blow Marshall Method. While this helped to assure higher asphalt binder content as well as the use of locally available materials, it also resulted in a number of pavement performance problems with respect to rutting, cracking and raveling (4). Following the completion of the work done under the Strategic Highway Research Program (SHRP) and the development of the Superpave Mix Design System in the mid 1990 s, FDOT began experimenting with the design and construction of Superpave mixes (5). The Superpave Mix Design represented a significant departure from the Marshall designed mixes and resulted in a number of significant improvements in Florida:

4 Stronger, more rut resistant mixes. As a result of the use of the Superpave Gyratory Compactor and higher gyration levels associated with higher traffic volumes, as well as the Superpave aggregate consensus properties, mixes in Florida were significantly stronger and were much less likely to rut. Historically softer aggregate sources (which had a history of rutting problems), were unable to meet the Superpave volumetric requirements and were no longer suitable for use. Mixes with large amounts of natural sand failed to meet the N initial mix design requirements, which significantly reduced the amounts of sand being used. In addition, crushed river gravel sources were unable to consistently meet the aggregate consensus properties, which ultimately led to their elimination. The use of stronger, more durable asphalt binders (specifically a polymer modified PG 76-22) also contributed greatly to the improved rutting resistance of these mixes. Mixture Consistency. Upon the adoption of the Superpave System, FDOT eliminated all leveling/sand mixes and focused on the use of three Nominal Maximum Aggregate Sizes (9.5 mm, 12.5 mm and 19.0 mm) for base, structural and friction course mixes. With the exception of open graded friction courses described below, all had to meet the standard Superpave design criteria. In addition to reducing the various types of mixes used, it also eliminated a number of mix types with a history of poor performance. Friction Courses As a result of the passage of the Highway Safety Act of 1966 by the United States Congress, the Federal Highway Administration (FHWA) in 1967 issued an Instructional Memorandum to state highway agencies requiring them to develop standards for pavement design and construction with specific provisions for high skid resistant qualities (6). This included a requirement to determine if the aggregate used in the top layer of asphalt pavements was capable of providing adequate skid resistance without polishing. Since the majority of asphalt pavements in service in Florida at that time were constructed using native materials prone to polishing, this requirement served as the catalyst for the evaluation of a variety of dense and open graded wearing courses. Following the construction and evaluation of numerous test sections around the state with varying aggregate types, specifications were finalized in 1975 for eight wearing course mixtures that would be used on the State Highway System in Florida (7). The Wearing Course (WC) mixtures were as follows: WC-1: Dense Graded Asphalt Concrete with Slag WC-2: Dense Graded Asphalt Concrete with Granite WC-3: Dense Graded Asphalt Concrete with River Gravel WC-4: Dense Graded Sand Asphalt Hot Mix WC-5: Open-Graded Asphalt Concrete with Oolitic Limestone WC-6: Open-Graded Asphalt Concrete with Slag WC-7: Open-Graded Asphalt Concrete with Granite WC-8: Open-Graded Asphalt Concrete with River Gravel

5 In 1974, the FHWA published guidelines and a design procedure for open graded friction courses, and, based on the success that western states had with plant mixed seal coats, encouraged states to adopt this technology (8). Florida s past experiences with open graded wearing course mixtures (both good and bad), coupled with these new FHWA guidelines, led to the development of specifications that were finalized in 1979 for a new open graded friction course, called FC-2 (9). The FC-2 mixture replaced the WC-5, WC- 6, WC-7, and WC-8 mixtures. It was designed with a modified version of the FHWA Pie-Plate method described in the 1974 design procedure. The FC-2 mixture was placed on all high-speed multi-lane facilities in an effort to reduce the risk of hydroplaning. FC-2 Open Graded Friction Course Composition and Construction Requirements: The FC-2 mixture had a 3/8 nominal maximum aggregate size (NMAS); utilized granite, slag, river gravel, or oolitic limestone for the aggregate; and also used unmodified asphalt cement (AC-30) for the binder. In 1994, the binder was changed from an AC-30 to an asphalt rubber binder consisting of AC-30 blended with 12% ground tire rubber. The mixture was produced at 240⁰F to minimize construction drain-down, and was placed at a minimum yield of 40 lbs/sy, or an approximate layer thickness of 1/2. The mixture was paid for on a square yard basis, and the specified rate of tack coat was 0.02 gal/sy of emulsified asphalt. Performance Issues: The porous texture of an OGFC exposes the thin film of asphalt on the aggregate in the pavement to heat, air, ultraviolet radiation and moisture, all of which cause the binder to oxidize and harden. This oxidative hardening makes the binder more brittle and less likely to behave as a flexible material. Under repeated traffic loads the binder fatigues and ultimately cracks, resulting in the aggregate particle raveling. The loss of one particle contributes to the loss of another particle and the problem becomes progressively worse. When open graded friction courses were first developed, FHWA estimated the service life to be from 5 7 years. In 1990 the FHWA issued a Technical Advisory on Open Graded Friction Courses and estimated the service life at that time to be from 7 10 years (10). As with other states, the primary source of failure with FC-2 OGFC mixtures in Florida was raveling. A number of issues contributed to this problem: Low binder content: Since the FC-2 mixtures used an unmodified binder and did not contain any type of stabilizing additive, drain-down of the binder off of the aggregate during construction was a persistent problem. To address this problem the FC-2 mixtures were designed with relatively low binder contents and were produced at lower temperatures. The low binder content resulted in a thinner film of binder on the aggregate, which exacerbated the aging problem. Lower production and placement temperatures also contributed to occasional texture problems during construction. Both of these contributed to the raveling problem. Layer Thickness: With a minimum spread rate of 40 lbs/sy required, and payment on a square yard basis, there was little incentive for a contractor to place the mixture thicker than 40 lbs/sy. In many cases, the layer was so thin that it led to a rough surface texture and ensuing performance problems.

6 Low tack coat: The specified rate of tack coat was 0.02 gal/sy of emulsified asphalt, with a residue asphalt rate of gal/sy, which was very low. FC-5 Open Graded Friction Course In 1998, based on positive feedback that the Georgia Department of Transportation (GDOT) had received on their D-Modified open graded friction courses, FDOT began the development of a similar type of OGFC, called FC-5. The FC-5 mixture has a 1/2 NMAS; uses granite or oolitic limestone; and also uses modified asphalt binder (either asphalt rubber with 12% GTR or a polymer modified PG 76-22). The FC-5 is placed at a thickness of 3/4. In order to increase the optimum binder content without an ensuing problem with drain-down during construction, the mixture contains fiber stabilizing additives (either mineral or cellulose) at a dosage rate of 0.4%. Production temperatures for FC-5 were also increased to 320⁰F. FC-5 mixes that contain granite were also required to use 1% hydrated lime to reduce the potential for stripping. The FC-5 is paid for by the ton and has a target yield that is based on the aggregate specific gravity; consequently, contractors can place the mix slightly higher than the target and will get paid for the material. The thicker layer coupled with higher production temperatures translated to a smoother surface with a more uniform texture. The specified tack coat rate was also changed to 0.05 gal/sy of emulsified asphalt, with a residual asphalt rate of gal/sy, almost three times the rate used for FC-2. The Specifications for FC-5 were finalized and were utilized in all projects beginning in January 2000 (11). In addition, many times FC-2 mixtures were used in locations that did not have a high risk of hydroplaning (turn lanes, cross-overs, lower volume roads); and they were bid as an alternative to a dense graded friction course. In the mid 1990s, FDOT s Flexible Pavement Design Manual was changed to require the use of FC-5 in specific areas. Other Factors Relating to Improved Pavement Performance: In addition to the changes made to the mix design processes, there were also other changes made that have contributed to an overall improvement in performance, such as: Adoption of CQC Specifications in 2002: In 1995, the United States Code of Federal Regulations (23 CFR 637B) was revised to allow contractor quality control testing to be used in the acceptance decision on Federal Aid Highway Projects (12). In July 2002, following a lengthy development and evaluation period, FDOT adopted Contractor Quality Control (CQC) specifications where the primary responsibility for the testing fell to the Contractor. The Contractor s test data, after being verified by FDOT, were used to calculate payment. Concurrent with this change, FDOT also adopted a percent within limits (PWL) approach for the acceptance and payment of all hot-mix asphalt, including FC-5. The goals of these changes were to: 1) increase the quality of road and bridge construction by requiring contractors to pay more attention to quality control; and 2) provide a mechanism to reward contractors for producing a product that matched the mix design and was consistent and uniform. This also resulted in the production of mixes that were controlled very closely with respect to volumetrics as well as binder content.

7 Construction Training and Qualification Program CTQP: 23 CFR 637B also added requirements that only qualified testing personnel be allowed to participate in the acceptance testing on Federal Aid projects. FDOT used this opportunity to develop a comprehensive set of training courses that focused on producing and placing a higher quality asphalt pavement. All plant and roadway technicians in Florida are required to be qualified under this program. Adoption of Warranty Specifications: In 2004, FDOT adopted Value Added Asphalt Pavement (VAAP) specifications which essentially serve as a three-year warranty on performance. Any raveling that occurs during the three year period following final acceptance of the project would require that the contractor take remedial actions or lose their pre-qualification status and not be allowed to bid on future FDOT projects. Usage: Many times, FC-2 mixtures were used in locations that did not have a high risk of hydroplaning (turn lanes, cross-overs, lower volume roads); and they were bid as an alternative to a dense graded friction course. In the mid 1990s, FDOT s Flexible Design Manual was changed to require the use of FC-5 in specific areas. PAVEMENT MANAGEMENT Title XXVI Section (4) (a) 1 of Florida Statutes states that the Department will ensure that 80 percent of the pavement on the State Highway System meets department standards. This threshold is used within the FDOT Pavement Management System to allocate resurfacing funds to ensure that this goal is met. The goal has been achieved since 2006 as shown in Figure 1.

8 100.0% 95.0% 90.0% 85.0% 80.0% 80.6% 80.1% 80.1% 79.7% 82.1% 83.5% 83.5% 85.6% 87.6% 88.9% 91.6% 90.6% % 78.8% 78.0% 75.0% Figure 1. Percent of State Highway System Not Deficient. In this context of the statutory requirement, FDOT pavement performance data have shown several interesting trends. First, the overall condition of state maintained pavements has been improving steadily as shown in Figure 1. Second, the improved performance of Florida pavements has been quantified using Survival Analysis. Survival Analysis considers the percentage of pavements of a type that become deficient with increasing age. The aggregate experience is illustrated in a plot as shown in Figure 2 for Open Graded Friction Courses. The key item in the figure is the age at which 50 percent of the pavement lane miles become deficient. This value is commonly known as the Service Life. In Figure 2, the Service Life for FC2 mix designs is about 12.2 years while the Service Life for FC5 mix designs is approximately 14.9 years.

9 Percent Not Deficient % 90.00% 80.00% 70.00% 60.00% 50.00% 40.00% 30.00% 20.00% 10.00% FC5 FC2 Median % Age (Years) Figure 2. Survival comparison of FC-2 versus FC-5 open graded friction courses. It should be noted, however, that the latter portion of the FC-5 curve uses relatively small samples sizes; therefore, the estimate of Service Life may not be exact. It should also be noted that the FC-5 friction courses are placed on Superpave structural courses, which may explain some of the difference in performance. In any case, the FC-5 mix design pavements, which are used on all Interstate and other high speed multilane facilities, are clearly lasting longer than FC-2. Survival Analysis was also applied to the Dense Graded friction course pavements with results shown in Figure 3. As yet, there is no statistical difference between the estimated lives for Superpave versus the Marshall Mix design dense graded friction course pavements. These friction courses are used on urban, two lane, and other facilities where the posted speed is less than 50 miles per hour.

10 % Percent Not Deficient 90.00% 80.00% 70.00% 60.00% 50.00% 40.00% 30.00% 20.00% 10.00% Superpave Marshall Median % Age (Years) Figure 3. Survival comparison of Superpave versus Marshall dense graded friction courses. In addition to its research into pavement materials, processes, and construction methods and management, FDOT has also invested in the development of a suite of programs that is used to track and predict future pavement performance and rationally allocate resources to resurface, rehabilitate, or reconstruct pavement sections at the most appropriate time. This suite is known as the Florida Analysis System for Targets (FAST). FAST has been used by FDOT managers to establish the level of funding necessary to address projected resurfacing needs over a given planning period to ensure that the statutory goals for nondeficient pavement are met. FAST is a suite of SAS -based computer programs that projects the future physical condition of pavement sections on the SHS. It provides improved project level condition forecasts as well as the ability to calculate future resurfacing targets based on the forecasted conditions. This tool has enabled FDOT to confidently reduce its resurfacing program and reallocate to capacity projects approximately $3 billion in non-essential resurfacing funds over the next ten years. FAST has been used to predict the impacts of varying levels of statewide resurfacing, expressed as a percentage of statewide lane miles. Departmental policy had been to resurface a specified percentage of the statewide lane miles annually by allocating a

11 proportion of the total statewide lane miles to each district based on the data acquired during the most recent Pavement Condition Survey (PCS). With improved forecasting models, FAST allows the resurfacing lane miles to be allocated using the projected deficiencies in future years. The Pavement Condition Forecasting Process The forecasts of future conditions are based on a family of mathematical equations relating pavement condition to pavement age. Significant variables in the process include surface type (i.e., open graded versus dense graded) and district. Each year, the mathematical models are updated by analyzing historical PCS data files. The models are calibrated using pavement condition and age data for the most recent calendar year. They are also tested for reasonableness over the previous five year period and validated with the current fiscal year pavement condition data. This annual analysis allows the performance impact of new pavement advances, such as FC-5, to be incorporated into updated forecasts for the next five year planning period. The forecasting of system pavement condition is based on the aggregate results of forecasting individual sections. The condition of each individual section is forecast based on the observed performance of the group of sections of which that specific section is a member. The algorithms by which the individual section conditions are forecast are based on the historic performance of the group. The definition of groups was determined using the statistical tool Analysis of Variance (ANOVA). ANOVA is useful in determining those factors that are significant in predicting the future values of variables like pavement condition. When ANOVA was applied to Florida s PCS database, it was determined that geographical location and type of friction course were the most significant factors in determining differences in pavement performance. Pavement age was also determined to be a significant factor. Predictive Model Development A number of traditional and exploratory models were developed and tested for predicting crack, rut, and ride rating for FDOT pavements. These included sigmoidal and other models suggested by the literature. However, it was judged that a piecewise linear model would work best for this application. The relationships between pavement condition and time were determined using linear regression. Values for each of the pavement condition variables were regressed versus pavement age for each combination of geographical area and friction course type. The regression model for each pavement condition variable was calibrated using the observed values in the PCS data for the previous year. The calibrated models were then used to predict values for current PCS year and validated using the observed values. FAST simulates the scheduling of future projects using processes based on benefit-cost ratios. The coefficients for the equations are recalculated each year using data specific to each combination of district and friction course type. The data are obtained from the results of the most recent PCS which is conducted annually for every section of pavement on the SHS. The result is a predictive curve for performance for each group.

12 Plots of the predictive equations for Open Graded Friction Course (OGFC) sections are shown in Figure 4. The equations for Dense Graded Friction Course (DGFC) sections are shown in Figure Crack Rating FAST Open D1 FAST Open D2 FAST Open D3 FAST Open D4 FAST Open D5 FAST Open D6 FAST Open D7 6.5 Threshold Age Figure 4. Predicted crack rating versus age by district for open graded surfaces.

13 Crack Rating 6 5 FAST Dense D1 FAST Dense D2 4 FAST Dense D3 3 FAST Dense D4 FAST Dense D5 2 FAST Dense D6 1 FAST Dense D7 6.5 Threshold Age Figure 5. Predicted crack rating versus age by district for dense graded surfaces. Application of the curves is specific to each member section in each district/friction course group. Using the latest PCS observation for a specific section, its age and observed value for the distress type (crack, rut, or ride) is compared to the corresponding value for the group predictive curve. The difference between the observed value for the section and the corresponding value for the group predictive curve is computed and carried forward to estimate performance in future years. This process is illustrated in Figure

14 Figure 6. Illustration of offset calculation and application FAST Data Requirements The primary data source for the FAST analysis is the internal Pavement Management SAS dataset PCSRCIWP. The PCSRCIWP dataset includes data integrated from three separate sources: the Pavement Condition Survey (PCS), the Roadway Characteristics Inventory (RCI), and the Work Program (WP) that are maintained by FDOT. PCS Data Source The PCS data source contains data on the condition history of the roadway segments comprising the state highway system. Pavement condition surveys are conducted annually over the entire system. Measurements of all three distress types (crack, ride, and rut) are taken and reported in the PCS data source. Each attribute is assigned to the specific section where it applies. These data are stored in files that use as their reference the beginning and ending points of the pavement condition survey. PCS sections are a minimum of 0.5 miles in length. These data provide the basis for producing predictive equations describing the performance of each pavement section with respect to the three distress types.

15 RCI Data Source The RCI data source contains average annual daily traffic, percent trucks, functional class, number of lanes, and other important information used in the FAST system. These attributes are assigned by logic that creates a new RCI section wherever any of the many values changes. The RCI sections can be as small as miles in length. WP Data Source The WP data source contains programmed project information such as project location and fiscal year of construction, which provides FAST with the ability to identify the roadway segments that have committed projects. The projects in the WP data source are defined with arbitrary limits that are determined by the beginning and ending point(s) of an upcoming project. Dynamic Segmentation Combining the three data sources, each with its own attributes and section beginning and ending limits requires a complex algorithm that analyzes the data from each on the incoming sources and constructs a new segmented file dynamically. The details of the dynamic segmentation are described elsewhere but the product of the combination process is a data set in which all of the data are included with a common set of beginning and ending mile points. Setting Resurfacing Targets FAST has been used to predict the impacts of varying levels of statewide resurfacing, expressed as a percentage of statewide lane miles. Departmental policy has been to resurface a specified percentage of the statewide lane miles annually by allocating a proportion of the total statewide lane miles to each district based on the data acquired during the most recent PCS. FAST allows the resurfacing lane miles to be allocated using the projected deficiencies in future years. The development of FAST allows the Department to allocate its pavement resurfacing resources among districts in a more efficient manner. One application of FAST has been the development of a resurfacing allocation procedure that determines district-specific pavement condition performance goals. Separate performance level targets can be allocated to each district, allowing a focus on future pavement performance rather than just lane mile targets. Within FAST, the rate of decline of pavement condition in each district is predicted based on the unique history of the pavement section conditions in that district. FAST accounts directly for future improvement projects that are included in the Work Program. The proportion of district Arterial pavement section inventory that is deficient is predicted for each future year.

16 Under this scenario, it is important that each district ensure that its overall pavement condition is within the prescribed proportion of their system at acceptable condition ratings. In order to meet this performance goal, each district will need to resurface a sufficient number of lane miles so that its predicted overall pavement condition proportion stays within the allowable limits. Since resurfacing funding has to be established for all districts several years in advance, a systematic method for determining how many lane miles they will need to resurface, and how much that will cost, is necessary. FAST provides this capability. EVALUATION OF ALTERNATIVE RESURFACING SCENARIOS FAST provides engineers the ability to evaluate the effect of different funding levels on the predicted condition of the SHS and to justify resurfacing budgets submitted to the state legislature. Analysis of statewide data indicates that a level of 77% of arterial roadway lane miles within acceptable condition will allow the Department to meet its statutory requirement of 80% within acceptable limits, assuming both the Interstate and Turnpike systems are at a 90% level. The 80% sufficiency level was determined to be an optimal level by a panel of Florida pavement experts in 1990 and has worked very well. It allows 20% of the pavement lane miles to show significant surface distress at any given time, but allows sufficient time for resurfacing projects to be designed and constructed as optimized preservation treatments before structural deterioration occurs. The 2012 PCS results showed that the state highway system had become more than 90% nondeficient, presenting an opportunity to reallocate additional funds from resurfacing. Consequently, FAST was run to evaluate several alternative funding scenarios to determine when and by what amount reductions could be made. The result of these efforts is that the percentage of statewide arterial roadways to be resurfaced over the period was reduced from 27.3 to This represented approximately $1 billion in savings in the current five year Work Program. Figure 7 shows the predicted system performance for both the current budget scenario and the revised scenario adopted in

17 100% 95% Percent Meeting Standards 90% 85% 80% 75% 70% 65% Scenario 1 (Current % 2013, 5.5% 2014, 5.3% 2015, 5.5% thru 2018) Scenario 2 w/adjustment (4% Critical LMs First, 4% ) Statute % Year Figure 7. Predicted system performance under the 2012 resurfacing scenarios. With receipt of the 2013 PCS data, the system had become 91.5% nondeficient and further FAST scenario analyses were performed, resulting in a reduction of the statewide arterial resurfacing level to 3% through Both the Interstate and Turnpike resurfacing levels were also reduced, resulting in reallocation of a total of $3 billion from the initial ten year baseline funding level. Figure 8 shows the resulting predicted performance.

18 100% 95% Percent Meeting Standards 90% 85% 80% 75% 70% 65% Interstate Turnpike Arterial (Proposed 3% ) SHS % Year Figure 8. Predicted system performance under the 2013 resurfacing scenario. CONCLUSION Florida s experience has shown that there is an excellent return on investment for research and development into pavement materials, processes, construction methods and management, and pavement management technology. Florida s pavements are lasting longer and management is able to reallocate resources that would have been programmed for resurfacing to providing much needed new capacity. FAST provides FDOT engineers and managers the ability to predict the future condition of its highway system. The annually calibrated, section level detail provided by FAST allows the effects of research and development initiatives to be directly quantified for the future. This tool has enabled FDOT to confidently reduce its resurfacing program and reallocate to capacity projects approximately $3 billion in non-essential resurfacing funds over the next ten years

19 REFERENCES 1) Florida State Road Department, Standard Specifications for Road and Bridge Construction, August 15, ) Telephone conversation with Mr. Charles F. Potts (FDOT State Bituminous Engineer from 1968 to 1980). 3) State of Florida Department of Transportation, Standard Specifications for Road and Bridge Construction, ) Page, G. C., Murphy, K. H., Musselman, J. A., West, R. C., An Assessment of Flexible Pavement Distresses on Florida s Highways Florida Department of Transportation Research Report No. FL/DOT/SMO/92-393, July ) Musselman, J. A., Choubane, B., Page, G. C., Upshaw, P. B., Experience with Superpave Implementation in 1996, Florida Department of Transportation Research Report FL/DOT/SMO/97-415, July ) United States Department of Transportation, Federal Highway Administration, Highway Safety Program Standard 12, June 27, ) State of Florida Department of Transportation, Supplemental Specifications to the 1973 Standard Specifications for Road and Bridge Construction, June ) Smith, R.W., J.M. Rice, and S.R. Spelman, Design of Open-Graded Asphalt Friction Courses, Report FHWA-RD-74-2, Federal Highway Administration, January ) State of Florida Department of Transportation, Supplemental Specifications to the 1977 Standard Specifications for Road and Bridge Construction, July ) United States Department of Transportation, Federal Highway Administration, Technical Advisory T , Open-Grade Friction Courses, December 26, ) State of Florida Department of Transportation, Standard Specifications for Road and Bridge Construction, January ) United States Code of Federal Regulations, Title 23 Highways, Chapter 1 Federal Highway Administration Department of Transportation, Subchapter G Engineering and Traffic Operations, Part 637 Construction Inspection and Approval, Subpart B Quality Assurance Procedures for Construction