Associates Traffic, Transportation & Civil Engineering Ali R. Khorasani, P.E. P.O. Box 804, Spencer, MA 01562, Tel: (508) 885-5121 Ms. Teri Ford, Associate 800 Boylston Street, Suite 1570 Boston, MA July 23, 2018 RE: Traffic Assessment for Proposed Industrial Manufacturing Development 85 Gilmore Drive, Sutton MA 01590 Dear Ms. Ford: AK Associates has prepared this memorandum assessing trips expected to be generated by the above referenced development and their impact on the available roadway network for the proposed land use in support of an application for the site plan approval in front of the Town of Sutton Planning Board. This assessment involved researching the Institute of Transportation Engineers (ITE) document Trip Generation for trip rates per 1,000 Square Feet (SF) of industrial land use. The evaluation was performed for assessing the adequacy of the existing area roadway network to handle the new trips expected to be generated by the proposed manufacturing development project. The proposed site is 19.8 acres in size and is located at the northerly end of Gilmore Drive, a cul-de-sac in Sutton, Massachusetts. The site will consist of a total of 180,000 square feet (sf), 140,000 sf of which will house the manufacturing component of this development, while the remaining 40,000 sf will provide for ancillary office space. The following sections describe each element of this evaluation. Existing Conditions: The proposed site is located on the west side of Gilmore Drive approximately 0.81 miles North of Main Street/Whitins Road, or at its northerly terminus. Gilmore Drive is a 2- lane, 2-way roadway that traverses in the northerly and southerly directions in the immediate vicinity of the proposed development site. Its pavement width varies from 30' to 34'. A sidewalk is provided on the west side of this street. The street has a slight vertical grade along its length (approximately 1%-2%), as well as some horizontal curvatures. The street is not posted with speed limit signs. However, the statutory prima facie speed limit of 30 miles per hour (mph) applies to this street. It serves a number of industrial land uses, in addition to the Lifesong Church. Finally, the proposed development site will be served by a common driveway that connects to the existing culde-sac at the northerly terminus of Gilmore Drive. Upon review of the site plan, it is concluded that the intersection of the proposed driveway with Gilmore Drive is located in such a way that it provides access to all parking spaces and loading areas in a safe
manner. The following figure 1 shows the general layout of the proposed industrial manufacturing development site that was prepared by Andrews Survey & Engineering, Inc. (ASE). Gilmore Drive intersects Main Street/Whitins Road at its southerly terminus forming a "T" intersection. The segment of Main Street to the west of Gilmore Drive changes its name from Main Street to Whitins Road and its pavement width is 32'. The posted speed limit is 30 mph. The pavement width of the segment of Main Street to the east of Gilmore Drive varies from 48' at the Route 146 ramps to 40' east of the ramps. It traverses under the Route 146 northbound/southbound overpasses and provides full access to Route 146. The posted speed limit for this section of Main Street is 35 mph. 2
Figure 1 Proposed Development Site 3
Traffic Volumes: The massdot database was researched for traffic volumes. There are no traffic volumes available for Gilmore Drive. However, there are traffic volume counts available from the massdot database for Whitins Road, at a point west of Route 146. The data shows that Whitins Road in the vicinity of Gilmore Drive has a daily volume of 4,485 vehicles, where trucks make up 0.7% of traffic volume, which is far less than average. The massdot database indicates that Main Street in the vicinity of Route 146 has a daily volume of 7,884 vehicles, 2.9% of which is truck traffic, which is about average for roads near industrial parks and divided highways. A copy of the traffic counts as well as a copy of a Bar Diagram for Main Street are shown in the following attachments. The northbound on-ramp has a daily volume of 2,238 vehicles, the northbound offramp has a daily volume of 1,665 vehicles, the southbound on-ramp has a daily volume of 1,414 vehicles, and finally, the southbound off-ramp has a daily volume of 2,424 vehicles. As can be seen, more vehicles get on and off from points north along Route 146. The peaking characteristics of the Main Street volumes are typical of other streets in the area where the morning peak hour two-way volume of 490 vehicles occurs between 7:00 am and 8:00 am, and while the afternoon peak hour two-way volume of 717 vehicles occurs between 5:00 pm and 6:00 pm. This information that is also graphically shown in the attachment, is intended to project a contrast as to what level of traffic might exist on Main Street. Finally, the massdot database shows that Route 146 at a point north of Lackey Dam Road carries a daily volume of 41,190 vehicles. A copy of the traffic counts as well as a copy of a Bar Diagram for Route 146 are also shown in the following attachments. Trip Generation: The magnitude of traffic volumes that will be generated by the proposed industrial development was projected by using the Trip Generation 1 document published by the Institute of Transportation Engineers (ITE). Based on the ITE Trip Generation document, the rates at which the proposed land use (Industrial, Land Use Code 120) generates traffic vary depending upon the time of day. The ITE rates were used to calculate the number of trips expected to be generated by the proposed site during an average weekday morning and afternoon peak traffic periods. A trip is defined as a vehicle either arriving at, or departing from the proposed site. This information is summarized in the following table 1. Table 1 ITE Trip Generation for General Industrial Land Use Code 120 Period AM Pk PM Pk Rates/1,000 sf 0.51 0.68 Total Trips 92 122 1 Trip Generation, Institute of Transportation Engineers; Washington, DC 4
As can be seen in the above table, the total number of new trips expected to be generated by the proposed industrial manufacturing development results in the highest traffic during PM peak period. Typically, the PM peak period represents the critical peak traffic volume on roadways. As shown in the above table 1, a total of 92 trips per hour will be either arriving at or departing from the proposed site during morning peak hour. Similarly, a total of 122 trips will be either arriving to or departing from the site during afternoon peak hour. It should be noted that this facility will be operating 3 shifts per day. Based on data from another existing site, the proposed development is expected to generate 10-15 truck trips during the 1st shift that includes UPS, FedEx and Box trucks for the purpose of delivering basic operational materials and office supplies. During the second shift, it is anticipated 3 to 5 trucks will be arriving at or departing from the site. Finally, no truck traffic is expected to arrive at or depart from the site during the 3rd shift. Therefore, the total truck traffic is not expected to exceed 20 per day. Considering Main Street peak hour traffic makes up 8.7% of the daily traffic, it is anticipated that less than 2 trucks would be on the road during that same time period, or one truck every 30 minutes. Therefore, the impact associated with the truck traffic from the proposed industrial site on Gilmore Drive, Whitins Road, Route 146 and Main Street will be insignificant. Stopping Sight Distances: Stopping sight distance is defined as the distance necessary for a vehicle traveling at the speed limit to stop before reaching a stationary object in its path. The sight distance at every point along a roadway should be equal to at least the stopping sight distance. Based on Basic Design Controls for roadway design, the stopping sight distance is calculated using the formula d=(v*v)/(30*f), plus the time required for perception and reaction by a driver (2.5 seconds). V is approach speed in mph, and f=0.28-0.35 (coefficient of friction). The stopping sight distances are calculated for different rates of speed and are provided in Exhibit 3-8 of the 2006 massdot Project Development and Design Guide. A copy of this exhibit is attached to this memorandum. The required stopping sight distances for a 30 mph on Whitins Road and 35 mph on Main Street are 200' and 250', respectively. The sight distances to the right (west) and left (east) of Gilmore Drive were measured in the field. The measured distances are those from a point 5' back of a stop bar (approximately 15' from the street line) and 3.5' above grade to represent drivers' eye height to an object 3.5' above roadway grade. The field review of the Gilmore Drive and Main Street intersection showed that the available sight line for the traffic coming out of Gilmore Drive is approximately 250' to the right (west), 5
and approximately 360' to the left (east). As stated earlier, no regulatory speed limit signs are posted on Gilmore Drive. As demonstrated herein above, available sight distances are greater than the required values for the northerly driveway. Traffic/Truck Traffic Circulation: It has been brought to our attention that some of the surrounding communities have expressed concerns over truck traffic bound for points along Interstate 495, will be traversing on some of the residential streets and local streets through town centers, thus disturbing the character of these communities. It should be noted that the biggest asset for this industrial park is its close proximity to Route 146, a divided highway that traverses northbound and southbound. Route 146 provides access to other major highways such as the Massachusetts Turnpike (I- 90), Worcester Expressway (I-290), Route 20, Route 122A, and I-395 to the north in Worcester, MA. Similarly, it provides access to I-295, I-95, I-195, and Route 6 to the south in Providence, RI. Most interstate highways have speed limits of 55 mph to 65 mph, which are twice the speed limit of those on local streets throughout surrounding communities. Also, travel on local roadways and through town centers are considered by truck drivers a lot more difficult when having to negotiate tight intersections and narrow streets. If a truck driver were to take local streets to get to I-495 in order to go to points north or south, it would take him much longer to get to the desired destination, and the difference in distance traveled would be minimal. For example, the distance traveled from the site to Marlborough, Massachusetts would be 3 miles shorter if a truck driver were to go through the center of Northbridge using Church Street when compared to traveling along Route 146 north to I-90, and then north along I- 495. However, the rates at which these trucks travel on divided highways are significantly higher than those on local streets, making it impractical. Similarly, if a truck driver is bound for points south and east, it would be a lot easier for the driver to utilize the interstate highways which would result in less wear and tear on the equipment due to stopping and starting at intersections and having to maneuver tight turns. Finally, it should be noted that more than 95% of trucks to and from the proposed site is by the developers account, and therefore, their route can be controlled by requiring them to use Route 146 and I-90 when going to points north, as well as Route 146, I-295, and I-95 when bound for points south. This can be ensured by issuing a directive to those trucking firms operating out of the proposed site. In conclusion, the proposed development is located in an industrial park with easy access to Route 146, a divided highway and major arterial. The proposed location of the common driveway for this site is proper. This driveway intersects the cul-de-sac that makes it easier for vehicles to enter and exit, particularly for large trucks. The driveway is wide enough at 30' to allow for two-way traffic and to accommodate larger vehicles. 6
The proposed use should have little or no impact on the area roadways, as they all have sufficient capacity to accommodate the new traffic expected to be generated by the proposed development. However, since the site common driveway, a private road, meets Gilmore Drive, a public street, it is recommended that a stop sign be installed at the end of the proposed common driveway facing the southbound traffic for vehicles exiting the site. I trust this memorandum and its recommendation will suffice. Please feel free to contact me should you have any questions. Sincerely, Ali R. Khorasani Ali R. Khorasani, P.E. Attachments 7
Main Street Volume LOCATION INFO Location ID 236920 Type SPOT Fnct'l Class 5 Located On MAIN STREET EAST OF RTE.146 Direction 2-WAY County Worcester Community Northbridge MPO ID HPMS ID Agency MHD INTERVAL:15-MIN 15-min Interval Hourly Time 1st 2nd 3rd 4th Count 0:00-1:00 22 8 10 0 40 1:00-2:00 7 7 5 7 26 2:00-3:00 2 4 3 5 14 3:00-4:00 2 7 7 10 26 4:00-5:00 13 7 10 11 41 5:00-6:00 11 38 28 43 120 6:00-7:00 59 73 110 142 384 7:00-8:00 116 119 124 131 490 8:00-9:00 124 111 107 99 441 9:00-10:00 100 79 98 91 368 10:00-11:00 95 107 103 109 414 11:00-12:00 92 122 105 121 440 12:00-13:00 117 128 120 123 488 13:00-14:00 110 113 92 108 423 14:00-15:00 131 137 140 166 574 15:00-16:00 171 136 173 168 648 16:00-17:00 171 189 165 167 692 17:00-18:00 201 174 173 169 717 18:00-19:00 163 151 153 126 593 19:00-20:00 120 131 123 94 468 20:00-21:00 95 75 96 64 330 21:00-22:00 60 48 52 46 206 22:00-23:00 46 23 30 32 131 23:00-24:00 14 15 18 10 57 Total 8,131 AADT 7,150 AM Peak 06:45-07:45 501 PM Peak 16:15-17:15 722 8
Main Street Volume Bar Graph 9
Route 146 Volume LOCATION INFO Location ID 3203 Type SPOT Fnct'l Class 2 PURPLE HEART Located On HIGHWAY Loc On Alias Worcester-Providence Turnpike AT SUTTON T.L. Direction 2-WAY County Worcester Community Douglas MPO ID HPMS ID 077006600300 Agency MHD INTERVAL:60-MIN Hourly Time Count 0:00-1:00 401 1:00-2:00 222 2:00-3:00 158 3:00-4:00 221 4:00-5:00 551 5:00-6:00 1,262 6:00-7:00 2,564 7:00-8:00 2,826 8:00-9:00 2,298 9:00-10:00 2,310 10:00-11:00 2,350 11:00-12:00 2,323 12:00-13:00 2,195 13:00-14:00 2,270 14:00-15:00 2,329 15:00-16:00 2,497 16:00-17:00 2,640 17:00-18:00 2,740 18:00-19:00 2,359 19:00-20:00 1,862 20:00-21:00 1,660 21:00-22:00 1,298 22:00-23:00 751 23:00-24:00 733 Total 40,820 AADT 37,840 AM Peak 07:00-08:00 2,826 PM Peak 17:00-18:00 2,740 10
Route 146 Volume Bar Graph 11