Traffic Evaluation and Access Management Report Douglas Woods Wind Farm Douglas,Massachusets Prepared for American Pro Wind 195 Libbey Parkway - Unit Two Weymouth, MA 02189 Prepared by Transportation, Land Development, Environmental Services Union Station, Suite 219 2 Washington Square Worcester, MA 01604 508-752-1001 Date: September 3, 2010 VHB Project Number 10913.01 \\Maworc\projects\10913.01\reports\Traffic\Traffic Evaluation and Access Management Report_090910 - Final.doc
Table of Contents Table of Contents... i List of Figures... ii Traffic Evaluation Summary... 1 Construction Activities... 1 Site Preparation Activities... 1 Wind-Turbine Construction Activities... 2 Post-construction Activities... 4 Pavement Impacts... 4 Daily Operations... 4 Traffic Evaluation Conclusions and Recommendations... 5 Wind Turbine Equipment Access... 6 Introduction... 6 Design Parameters... 6 Transport Vehicles... 6 Roadway Networks... 7 Local Roadway Networks... 7 Regional Highway Network Evaluation... 8 Wind Turbine Equipment Access Conclusions and Recommendations... 9 \\Maworc\projects\10913.01\reports\Traffic\Traffic Evaluation and Access Management Report_090910 - Final.doc i Traffic Evaluation and Access Management Report
List of Figures Figure No. Description Following 1 Site Locus USGS Map... Page 1 2 I-395 NB Off-Ramp... Page 7 3 I-395 Off-Ramps at Gore Road... Figure 2 4 Gore/Douglas Road Intersection... Figure 3 5 Entrance to Site... Page 9 \\Maworc\projects\10913.01\reports\Traffic\Traffic Evaluation and Access Management Report_090910 - Final.doc ii Traffic Evaluation and Access Management Report
Traffic Evaluation Summary At the request of the Town of Douglas Planning Board as part of the evaluation of the traffic associated with the development of the Douglas Woods Wind Farm (the Project) to be constructed in Douglas, Massachusetts, Vanasse Hangen Brustlin, Inc. (VHB) has prepared the following memorandum to document the anticipated transportation impacts associated with the Project. Note that these estimates are based on discussions with the developer and their contractors as well as VHB s experience on similar projects. The Project consists of the construction of a commercial-scale wind energy facility consisting of 11 wind turbines on a 298-acre site (the Site) located off Webster Street (Route 16) in Douglas, Massachusetts. The Site is located just west of the intersection of Webster Street and Old Douglas Road at the municipal boundary between the Town of Douglas and the Town of Webster. See Figure 1 Site Locus USGS Map. Due to the oversized nature of each of the wind turbines, multiple delivery trucks will be required to transport the components of each wind turbine. Therefore, the transportation evaluation focuses not only on the daily trips to be generated during normal operations, which are minimal, but also on those vehicle trips to be generated during construction-related activities. Construction Activities It is expected that construction-related activities will take place over the course of a three- to six-month period. These activities will involve site preparation activities including road and crane pad construction, foundation construction; and windturbine delivery and erection. Site Preparation Activities Because of the variable nature of the construction-related activities, transportation impacts will also vary depending on the nature of the activities ongoing during any particular period. This analysis is intended to provide a general overview of the construction-related impacts. Initially, construction-related activities will include land clearing and earthworks necessary for the wind turbine sites, construction of access roadways, and other utility-based activities. It is envisioned that 20 to 40 construction workers will be at \\Maworc\projects\10913.01\reports\Traffic\Traffic Evaluation and Access Management Report_090910 - Final.doc 1 Traffic Evaluation and Access Management Report
the Site at any given time during normal construction hours as part of this phase. Construction equipment will be stored on site and therefore will not need to be trucked into and out of the Site on a regular basis. Additionally, the project team does not envision a large volume of earth moving onto or off the site, thus it is not anticipated that the Project will produce large numbers of off-site vehicle trips daily related to earth moving. While specific activities will be better defined when the site plan is finalized and a contractor is selected, it is envisioned that the earthworks component of the Project will include 20 to 30 trips for initial delivery of large equipment to the site along with the daily recurring delivery of some construction materials (concrete, asphalt, and other materials). Additionally, approximately 50 deliveries will be required for each of the wind turbine pads in order to build suitable foundations for the turbine. In completing this analysis, VHB has assumed the following trip generation during the three- to six-month construction phase of the Project: Approximately 20 to 30 over-sized haul trips as construction equipment is delivered to the Site. It is anticipated that these trips will connect to Route 16 from either I-395 in Webster or Route 146 in Douglas. Recurring traffic impacts along Route 16 will include approximately 60 to 120 daily trips associated with the construction workers and 10 to 20 delivery trips of construction-related materials. It is anticipated that these trips will connect to Route 16 from either Route 395 in Webster or Route 146 in Douglas. Last, each turbine pad will also see approximately 50 concrete and material deliveries as needed. By way of comparison, Route 16 just west of the I-395 interchange in Webster carries approximately 15,900 1 vehicles per day so the impact of 60-120 daily passenger vehicle trips will be negligible (less than 1%) from an operational perspective during the construction timeframe. Wind-Turbine Construction Activities Once construction activities associated with the erection of the wind turbines commences, the most significant transportation impacts will be associated with the delivery of the larger components of the wind turbines. From a numerical perspective, each wind turbine will have approximately 10-13 deliveries comprised of tower segments, the nacelle, and wind blades. Because of the equipment size, these haul vehicles will be oversized and will require escort vehicles from their manufacturing plant all the way to the Site. 1 Massachusetts Highway Department, Traffic Volume Handbook (2006); Count Station 3208, Route 16, East of Route I-395; 2005 data. \\Maworc\projects\10913.01\reports\Traffic\Traffic Evaluation and Access Management Report_090910 - Final.doc 2 Traffic Evaluation and Access Management Report
A materials access memorandum has already been prepared documenting the practical issues associated with hauling large equipment to the Site over Massachusetts roadways. Before deliveries are scheduled, the wind turbine manufacturer and hauling contractor will conduct a full route survey along Massachusetts state and local roadways along with a longer transport route assessment from the manufacturing facility to the Site. The turbine manufacturer and hauling contractor will be responsible for acquiring oversized vehicle permits from the appropriate transportation regulatory authorities. This will include specifically identifying conflict points along the travel route, addressing them to the satisfaction of the regulatory authorities, and meeting all permit conditions. Typically, oversized deliveries of this type require escort vehicles. It is anticipated that two vehicles will escort each oversize load one each in the front and back of the haul vehicle. For each of the wind turbine pads, oversized components will be delivered to the Site over a two-day period, with one turbine delivery per week. Therefore, 60 to 78 trips will be generated during the approximately 11-week construction period. Deliveries are likely to occur during daylight hours, yet outside of peak commuter periods. However, as part of the oversized vehicle permit process, MassDOT and the Massachusetts State Police will specify the time of day most appropriate for deliveries to minimize impacts on local and interstate roads with input from local authorities. Similar to the wind turbine components, oversized equipment such as elements of the crane erection equipment may require oversized deliveries to the Site as well. The crane components will be delivered early in the process and will move internal to the Site between wind turbine pad locations. Through discussions with the crane providers, it is estimated that approximately 12 to 20 deliveries will be required to deliver the crane components at the outset of the three- to six-month construction process. To summarize, wind turbine construction phase will see the following trip generation impacts along local roadway: Traffic impacts associated with the delivery of oversized wind turbine equipment will be permitted through MassDOT with input from the Massachusetts State Police and local authorities and will be limited to approximately 10 to 13 escorted truck trips over a two-day period, every week for approximately 11 weeks. Similarly, traffic impacts associated with the delivery of crane equipment will be limited to a one-time impact of 12 to 20 deliveries of individual crane components prior to the wind turbine deliveries along Route 16. Once delivered, the equipment will remain on the Site and will not impact Route 16 operations until such a time that the construction equipment needs to be moved \\Maworc\projects\10913.01\reports\Traffic\Traffic Evaluation and Access Management Report_090910 - Final.doc 3 Traffic Evaluation and Access Management Report
off site. Obviously, the wind turbine components will remain on site and will not need to be escorted off the site. ALL DELIVERIES of an oversized nature will travel locally along Route 16 between I-395 and the Site. Post-construction Activities Pavement Impacts Once construction of the wind turbines has concluded, construction equipment will need to be hauled off the Site. In some cases (crane components), escort vehicles for oversized loads will be necessary. Otherwise, all post-construction activities will likely be phased out over the course of a two- to three-week period with impacts to traffic operations being minimal (five to ten truck trips per day as equipment is hauled away from the site). Experience with these developments has shown that the recurring delivery of oversized vehicles will result in some degradation of the pavement quality near the Site driveway and along the access route to the site. For this reason, it is typical that the Contractor and delivery companies will conduct a thorough review of the pavement and shoulder quality near the Site entrance including the collection of photo documentation of the road with representatives of the host community. This information will be provided to the Town of Douglas. As part of this effort, the Contractor will post a bond of an agreed upon amount needed to repave/reconstruct the access roadways to/from the Site and bring them back to their pre-construction condition. At the completion of the Project, another review of the roadway will be completed and the Contractor will be responsible to repair damage to Route 16 that was the result of the Project. Daily Operations Through discussions with the wind turbine manufacturer, it is expected that the Project will employ two full-time maintenance employees who will be stationed on the Site during normal working hours. These two employees are expected to generate approximately 10 vehicle trips per day (less than 0.1%), and it is VHB s opinion that the long-term traffic impacts of the Project will be negligible. \\Maworc\projects\10913.01\reports\Traffic\Traffic Evaluation and Access Management Report_090910 - Final.doc 4 Traffic Evaluation and Access Management Report
Traffic Evaluation Conclusions and Recommendations The overall traffic impacts resulting from the Project are expected to be minimal. The delivery of the large wind turbine equipment will temporarily disrupt normal traffic flow along this route during specific times of the day; however, these disruptions will be carefully planned and coordinated with the Towns of Douglas and Webster, the Massachusetts State Police, and MassDOT so that all parties are aware of the potential impacts as well as letting the public know of any potential disruptions. To minimize any impacts of the Project it is recommended that: The Towns of Webster and Douglas are included on any oversized vehicle permit applications so that issues of timing and delivery routes can be considered. All oversized deliveries occur along Route 16 between I-395 and the Site to limit impacts to local streets within Douglas and Webster. The driveway to the Project is designed to accommodate the turning movements of the oversized vehicles as they enter/exit the Site (see following chapter on routing summary for more information). The Contractor will provide the Towns of Douglas and Webster with a traffic management plan reflecting the goals and statements made in this memorandum as part of the construction permit application. The Contractor will be required to conduct a pre- and post-construction pavement quality survey of Route 16 in the vicinity of the Site entrance and will post a bond to guarantee that any damage resulting from the Project are repaired as needed. \\Maworc\projects\10913.01\reports\Traffic\Traffic Evaluation and Access Management Report_090910 - Final.doc 5 Traffic Evaluation and Access Management Report
Wind Turbine Equipment Access Introduction VHB has conducted a preliminary evaluation of access to the potential American Pro Wind LLC site in Douglas, Massachusetts. The purpose of this technical memorandum is to summarize the general findings of our investigation and to identify potential challenges from a transportation delivery perspective. Please note that this evaluation is based on field observations and information available to us at the time of this memorandum preparation. It includes information discussed with local officials, property owners, and other interested stakeholders, observations made during site visits, previous studies, and aerial photography. Design Parameters For the purposes of this evaluation, VHB has focused its study on the ability to transport various sized wind blades up to 50 meters in length and other large objects via truck to the Douglas site. Ultimately, any delivery vehicle of this size will need to obtain a heavy load permit from the Massachusetts Department of Transportation (MassDOT) and will need to conduct a full engineering route evaluation that would focus on the technical details of the delivery route and vehicle. As a baseline condition for maximum load lengths, this assessment is based on the delivery of 50- meter blades to the site from locations to be determined. Transport Vehicles Before evaluating the various possible limitations for the routes to the project site, it is critical to understand the nature of the vehicles transporting the blades2 to the site. Traditional tractor-trailer vehicles do not provide the flexibility and steering capabilities that today s larger transport vehicles utilize. Based on previous research of vehicles in use today for transporting loads of this type by the heavy hauling industry, most providers are using a rear steerable trailer to improve turning radii and reduce over-tracking onto adjacent properties. Over-tracking is the exaggerated 2 Note: Throughout this memorandum, the term blades is generically utilized and can refer to any static object of significant length being transported. \\Maworc\projects\10913.01\reports\Traffic\Traffic Evaluation and Access Management Report_090910 - Final.doc 6 Traffic Evaluation and Access Management Report
footprint, or dynamic envelope, of the rear portion of the transport and the load being carried as the transport turns along the roadway. Due to the extended nature of these loads, over-tracking is realized along the entire length of the load as the transport negotiates any turning movement. These vehicles are different than traditional tractor trailer combination vehicles in that they are steered from both the front cab of the transports tractor as well as the rear axle of the trailer supporting the load. Having the rear-wheel maneuverability provides significantly greater flexibility in negotiating tighter turns as well as dealing with the overhang of the transport s load. The vehicle transport type used in this evaluation is a typical oversized load vehicle commonly used and having the following dimensional specifications: Transport tractor and load carrying trailer have a combined length of 182 feet which articulates about a point located approximately 18 feet from the front of the tractor; The track width of the tractor and trailer used (this is the width of the vehicle excluding the load being carried) is 8 feet 6 inches; The width of the load is assumed to be 15 feet based on a root diameter of 14 feet for a 50 meter blade (this dimension is as provided in a previous study completed for the Massachusetts Technology Collaborative) thus allowing a 6 inch buffer along the width of the loads widest point. Should a vehicle of different dimensions be used, it is recommended that further evaluation be undertaken to verify the findings of this study. Roadway Networks Based on VHB s evaluation of the Interstate Systems connecting to the local roadway network and the immediate area surrounding the project site, the local roadway system is lightly developed and would pose some turning radius issues and point obstructions (i.e. utility poles/wires or other roadside obstructions) for any hauling provider. These would need to be evaluated and addressed as part of a more detailed route evaluation. Local Roadway Networks Transport vehicles accessing the local roadway network from I-395, north or south, would exit the highway at Interchange 2, which provides access to Route 16/Gore Road. Gore Road, within the area of the interchange, is a 3-lane roadway with narrow shoulders located in the Town of Webster with light mixed-use development \\Maworc\projects\10913.01\reports\Traffic\Traffic Evaluation and Access Management Report_090910 - Final.doc 7 Traffic Evaluation and Access Management Report
along the roadways perimeter. The area within the interchange presents tighter than desirable turning radii and roadside obstruction issues (See Figures 2, 3 and 4). There is no posted substandard bridge clearance for the I-395 overpasses located at Gore Road but existing available clearance would need to be verified in a more detailed review of this route. Gore Road continues easterly and provides the connection to Douglas Road, which becomes Webster Road upon entering the Town of Douglas at the Project Site. Douglas/Webster Road is a 2-lane roadway with narrow shoulders. Based on field observations, both Gore Road and Douglas/Webster Road make their way through business and residential areas, which present roadside and overhead clearance obstructions (guardrail, utilities lines and vegetation) that will require additional investigation and will likely need to be addressed as part of the route survey. The entrance to the site would require a wide clear area around the driveway (40 minimum) along the eastern edge of the road frontage parcel and provide a soft sweeping curvature as it enters the site (See Figure 5). This is to minimize overtracking of the rear end of long loads due to the narrow nature of the existing Webster Road footprint and limited roadside clearance of vegetation near the site. Regional Highway Network Evaluation The local roadway network can be accessed from Interstate 395 (I-395) in either direction. I-395 is connected to I-290 to the north and I -95 to the south in Connecticut. I-290 serves as a connector to both I-495 and the Massachusetts Turnpike (I-90). I-495 also provides connectivity to I-93 further to the north and I-95 to the south within Massachusetts. I-290 is an urban highway through downtown Worcester but appears to present no real obstacles for transporting large loads. The limiting factors on all of these interstate roadways are: available bridge clearance at overpasses; available bridge load carrying capacities; and turning radii within the connecting interchanges The Federal Highway Administration (FHWA) required that all interstate bridges needed to be at least 14 feet, 6 inches in height during their construction in the 1950s, 1960s, and 1970s. During their construction, a number of waivers were provided for substandard bridge heights on both pre-existing bridge locations as well as in certain other cases. Since that time, the current standards require that all new bridges on Interstate highways be at least 16 feet, 6 inches. As the Massachusetts highway system was constructed several decades ago, most bridges meet the minimum clearances of 14 feet, 6 inches. Additionally, the minimum clearance for overhead \\Maworc\projects\10913.01\reports\Traffic\Traffic Evaluation and Access Management Report_090910 - Final.doc 8 Traffic Evaluation and Access Management Report
Figure 2
Figure 3
Figure 4
guide signs is 17 on interstates by guideline but a field evaluation would need to be done to verify actual clearances along the entire delivery routes. A bridge loading evaluation would also need to be completed along the desired route based on the characteristics of the actual transport vehicles being employed and load being carried prior to confirming viability of intended delivery routes. Based on research of the possible transport routes mentioned previously, there are substandard clearances posted on I-90, I-395, I-95 north of I-90, I-95 south of I-90 and I-93. The Massachusetts Turnpike (I-90) has several substandard bridge clearances most of which are posted at 14 feet making transport of large loads difficult along this route. I-395 has one substandard posting located just north of Interchange 1 in Webster at 14 feet 2 inches where Birch Island Road passes over the highway. In addition to the bridge clearance issues, VHB also determined through the field review that the Massachusetts Turnpike (I-90) to I-395 connection would be virtually impossible for a transport vehicle to maneuver through carrying a 50-meter blade. Wind Turbine Equipment Access Conclusions and Recommendations Based on this evaluation, it has been determined that: Depending on the size of the transport vehicle and blade size, there appears to be some minor obstructions and/or physical limitations along the local roadway network to the Project Site in Douglas. These obstructions, however, do not appear to be critical in nature and could likely be addressed through temporary relocation of utility poles, signage, clearing of vegetation, and/or traffic management techniques during the construction periods; Should 50-meter blades be transported to the site, there are a few point-source obstructions along local route that require additional investigation in, around, and under the I-395 interchange; and The Massachusetts interstate/regional roadway system can deliver up to 50 meter blades using certain routes to (and from, if needed) the project site with the notable exceptions of a few limiting bridge clearances, and the I-90/I-395 interchange in Auburn; In order to transport any significant objects using local or state highways within the Commonwealth of Massachusetts, an in-depth engineering review will ultimately need to be conducted to fully evaluate the specifics of the transport routes in support of a permit application with MassDOT. \\Maworc\projects\10913.01\reports\Traffic\Traffic Evaluation and Access Management Report_090910 - Final.doc 9 Traffic Evaluation and Access Management Report
Figure 5