P ARE Pr o je c t No . 0 71 36 . 00

REPO RT

TRAFFIC IMPACT ANALYSIS

NORTH VILLAGE RESIDENTIAL DEVELOPMENT

DOUGLAS, MASSACHUSETTS

Proponent: Heritage Design Group

One Main Street Whitinsville, MA 01588

Prepared By: Pare Corporation

8 Blackstone Valley Place Lincoln, RI 02865

Submitted March 7, 2008 Revised November 14, 2008

i

TABLE OF CONTENTS

DESCRIPTION PAGE

INTRODUCTION 1

DATA COLLECTION 1

EXISTING ROADWAY CONDITIONS 5

North Street and Gilboa Street 5

North Street and Pond Street 6

North Street and Gilboa Court 6

Whitins Road/Hough Road and Barnett Road 6

EXISTING TRAFFIC VOLUMES 7

SAFETY ANALYSIS 10

Crash Data 10

Speed Data 10

Stopping Sight Distance 11

Intersection Sight Distance 12

FUTURE CONDITIONS 12

Background Growth 13

Anticipated Development 13

2012 BUILD CONDITIONS 16

Trip Generation 16

Trip Distribution 17

CAPACITY ANALYSIS EXISTING AND FUTURE BUILD CONDITIONS 17

Intersections 18

CONCLUSIONS 22

Figures Figure 1: Locus Map 3

Figure 2: Conceptual Site Plan 4

Figure 3: 2007 AM Peak Existing Volumes 8

Figure 4: 2007 PM Peak Existing Volumes 9

Figure 5: 2012 AM Future No Build Volumes 14

Figure 6: 2012 PM Peak Future No Build Volumes 15

Figure 7: 2012 AM Future Build Flow Chart 20

Figure 8: 2012 PM Future Build Flow Chart 21

ii

TABLE OF CONTENTS

DESCRIPTION PAGE

Tables Table 1: Spot Speed Results for North Street 11

Table 2: Trip Generation Summary 16

Table 3: LOS Criteria for Unsignalized Intersections 17

APPENDICES

Appendix A Traffic Counts Appendix B Safety Data

Appendix C Trip Generation & Distribution

Appendix D Traffic Capacity Analysis

Appendix E Level of Service Tables

-1-

INTRODUCTION

Pare Corporation (PARE) was retained by Heritage Design Group to perform a traffic impact

analysis for the proposed North Village Residential Development located on North Street in

Douglas, Massachusetts. The development is proposed to include two separate sections: 105

residential condominiums/townhouses and 28 single family detached houses. A separate access

for each section of the development is proposed on North Street between Brown Road and

Colonial Road. Brown Road represents the town line between Douglas and Sutton,

Massachusetts.

Included in this report are existing conditions in the vicinity of the project site, a safety analysis

of the study area, an analysis of the anticipated traffic based on existing 2007, future 2012 no-

build and future 2012 build conditions, and proposed mitigation measures, if required. Existing

2007 conditions represent current conditions based on recent traffic counts and future 2012 no-

build conditions include trips generated by an increase in growth expected in the area without the

construction of the development. The future 2012 build condition represents the future 2012 no-

build condition plus the traffic expected to be generated by the proposed development. A locus

map of the study area is provided in Figure 1 and a conceptual plan for the site is provided in

Figure 2.

DATA COLLECTION

Manual turning movement counts were completed at all study area intersections on Wednesday,

November 14, 2007 and Thursday, November 15, 2007 between the hours of 6:00 to 9:00 a.m.

and 4:00 to 6:30 p.m. Time periods were selected to coincide with the hours of peak traffic and

peak commuter traffic. The volumes obtained were used in the capacity analysis at the

intersections. The study area intersections counted included the following:

• North Street/Gilboa Street (Douglas, MA)

• North Street/Pond Street and Gilboa Court (Douglas, MA) – Two separate 3-way

intersections

• Whitins Road/ Hough Road and Barnett Road (Sutton, MA)

-2-

Brown Street is also located within the study area, but has only two residential properties. Due to

the low volume of vehicles utilizing Brown Street, no traffic counts where perform at the

intersection of North Street and Brown Street. A copy of the traffic count data is provided in

Appendix A.

Automatic traffic recorder (ATR) counts were completed by DATA, Inc. from Wednesday,

December 5, 2007 to Thursday December 6, 2007 on North Street within the project area. Copies

of the ATR count data are provided in Appendix A.

Crash data was requested from the Town of Sutton Police Department and The Town of Douglas

Police Department on November 9, 2007 and was received on November 23, 2007. Additional

crash data was requested and received from the Massachusetts Highway Department

(MassHighway) on November 9, 2007. A copy of the data requests and tables summarizing the

data received are provided in Appendix B.

-5-

EXISTING ROADWAY CONDITIONS

This section describes the roadway network in the study area, surrounding the proposed project.

Land uses surrounding the project site are primarily residential uses. Included in the study area

for North Village Residential Development are four existing unsignalized intersections and the

two proposed access roads to the development. The intersections investigated include:

• North Street/Gilboa Street (Douglas, MA)

• North Street/Pond Street (Douglas, MA)

• North Street/Gilboa Court (Douglas, MA)

• Whitins Road/Hough Road & Barnett Road (Sutton, MA)

A field review of the entire study area was conducted, with field observations recorded at critical

intersections. In addition to the existing intersections, the proposed locations of the site entrances

were also investigated. A description of each intersection is provided below.

North Street and Gilboa Street

The intersection of North Street and Gilboa Street is a four-legged unsignalized intersection

located south of the proposed project site. North Street runs in a north/south direction and Gilboa

Street runs in an east/west direction. Gilboa Street provides direct access to Route 146 east of the

intersection. The northbound approach to the intersection, on North Street, has one 13-foot lane

northbound with one 12-foot lane southbound. The southbound approach to the intersection has

one 18-foot lane northbound with one 12-foot lane southbound. The eastbound approach to the

intersection, on Gilboa Street has one 13-foot lane westbound with one 14-foot lane eastbound.

The westbound approach to the intersection has one15-foot lane on both directions. Directional

traffic at this intersection is separated by a solid double yellow line. The posted speed limit on

North Street is 25 miles per hour and the posted speed limit on Gilboa Street is 25 miles per hour.

Crosswalks are marked across the eastbound and southbound approach to the intersection. This

intersection is 3-way stopped controlled, with the westbound approach operating uncontrolled.

-6-

North Street and Pond Street

The intersection of North Street with Pond Street forms a three-legged unsignalized intersection

located south of the proposed project site. North Street runs in a north/south direction and Pond

Street runs in an east/west direction. Both roadways carry two-way traffic. The northbound and

southbound approaches to the intersection, North Street, have one 11-foot lane northbound with

one 12-foot lane southbound. Directional traffic on these approaches is separated by a solid

double yellow line. The eastbound approach to the intersection on Pond Street is approximately

24 feet wide and is stop controlled at the intersection. The northbound and southbound

approaches operate with no controls. The posted speed limit on North Street is 25 miles per hour,

while Pond Street has no posted speed limit.

North Street and Gilboa Court

The intersection of North Street with Gilboa Court forms a three-legged unsignalized intersection

located south of the proposed project site. North Street runs in a north/south direction and Gilboa

Court runs in an east/west direction. Both roadways carry two-way traffic. The northbound and

southbound approaches to the intersection, North Street, have one 12-foot lane northbound with

one 11-foot lane southbound. Directional traffic on these approaches is separated by a solid

double yellow line. The westbound approach to the intersection on Gilboa Court is

approximately 17 feet wide and is stop controlled at the intersection. The northbound and

southbound approaches operate with no controls. The posted speed limit on North Street is 25

miles per hour, Gilboa Court has no posted speed limit.

North Street at the Proposed Site Driveways

In the area of the proposed site driveways, North Street is a meandering, moderately-hilly

roadway. The approximate roadway width at the northern site entrance is 18 feet, while the

approximate roadway width at the southern site entrance is 20 feet. At both locations, the

roadway is striped with a solid double yellow centerline, and no sidewalks or curbing are present.

Residential driveways are located along the length of North Street, however, their frequency is

greater south of the proposed site. North of the proposed site towards Sutton, fewer driveways

are located, with the houses having increased frontage on North Street.

-7-

Whitins Road/Hough Road and Barnett Road

The intersection of Whitins Road with Hough Road and Barnett Road forms a four-legged

unsignalized intersection located north of the proposed project site. The eastbound approach to

the intersection, Whitins Road has one 17-foot lane westbound with one 14-foot lane eastbound.

The westbound approach to the intersection has one 13-foot lane westbound with one 14-foot lane

eastbound. Directional traffic on this approach is separated by a solid double yellow line. The

northbound approach to the intersection, on Hough Road, is generally 26 feet wide and is stop

controlled at the intersection. The southbound approach to the intersection, on Barnett Road, is

generally 27 feet wide and is stop controlled at the intersection. The eastbound and westbound

approaches operate with no control. Both the Sutton Senior Center and Town recreational fields

are located along Hough Road north of the proposed site and south of Whitins Road. The posted

speed limit on Whitins Road is 35 miles per hour.

EXISTING TRAFFIC VOLUMES

Based on the traffic counts completed, the peak hours of the roadway network were determined to

occur from 7:00 to 8:00 a.m. and 4:15 to 5:15 p.m. on a typical weekday. The existing peak hour

volumes are shown in Figures 3 and 4.

Automatic traffic recorder (ATR) counts conducted over a 24-hour period from Wednesday,

December 5, 2007 to Thursday December 6, 2007 on North Street provide additional existing

traffic volume data for the study area. North Street on a typical weekday carries approximately

931 vehicles. Based on the MassHighway 2007 Weekday Seasonal Factors for Urban Arterials

and Collectors, the ADT for the roadway is expected to be approximately 960 vehicles per day.

The typical weekday split between the northbound and southbound directions is approximately

54% southbound and 46% northbound. Complete ATR count data and Mass Highway Seasonal

Factors are provided in Appendix A.

-10-

SAFETY ANALYSIS

The roadway network surrounding the proposed site area was analyzed with respect to crash

history and sight distance to determine potential crash patterns and roadway deficiencies. .

Crash Data

To identify potential crash patterns and roadway deficiencies, crash data for the most recent

three-year period was requested from the Town of Sutton Police Department, Town of Douglas

Police Department and the Massachusetts Highway Department (MassHighway) for the entire

study area. A summary of the data received is summarized in Appendix B. A review of the

accident reports indicates that the crash rates calculated at the study area intersections are less

than the MassHighway statewide and District 3 average crash rates. A total of 12 crashes were

reported at the unsignalized intersections between 2004 and September 2007 that could be located

based on the information provided.

Three of the crashes reported at the intersections were rear end crashes, seven were broadside,

and two were loss of control. Rear end collisions often occur at intersections and are typically the

result of driver inattention. The loss of control was due to snow conditions. Most of the

broadside crashes were result of drivers failing to stop at stop sign and most occurred at the

intersection of North Street and Gilboa Street. This four-legged intersection is stopped controlled

on three of the approaches northbound, southbound and eastbound. The westbound approach is a

free movement with no stop control. It is a possibility that some motorists approaching the

intersection may think that all four legs of the intersection are stop controlled, creating confusion.

Placing an additional stop sign on Gilboa Street eastbound approach may safely improve the

intersection. All twelve crashes involved property damage only, with no reported injuries. The

severity and frequency of crashes in the study area does not indicate a significant safety problem.

Based on this, no improvement is recommended to reduce the number of future accidents.

Speed Data

A speed study was conducted on North Street within the study area to determine average travel

speeds and the appropriate design speeds on the roadway. Data was recorded by DATA, Inc. on

Wednesday, December 5, 2007. The results are shown in Appendix A and summarized in the

table below.

-11-

Table 1: Spot Speed Results for North Street

Posted Speed

Average Speed

True Median

(50th Percentile)

85th Percentile

10 MPH

Pace

Percent of vehicles over

25 MPH

Northbound 25 30 32 38 26-35 79

Southbound 25 35 37 42 31-40 87

Speeds were recorded for 430 cars in the northbound direction and 501 cars in the southbound

direction. The posted speed limit on North Street is 25 miles per hour. Northbound on North

Street, the average speed measured was 30 miles per hour, with an 85th percentile speed of 38

miles per hour. Of the 430 cars observed, 79 percent had speeds over 25 miles per hour.

Southbound on North Street, the average speed measured was 35 miles per hour, with an 85th

percentile speed of 42 miles per hour. Of the 501 cars observed, 87 percent had speeds over 25

miles per hour.

Given the current travel speeds on North Street, it is recommended that intersection warning signs

be posted on the roadway in both directions in advance of the proposed site driveways. These

signs will warn motorists of the increased likelihood of entering traffic and potentially slow travel

speeds along the roadway. In addition, centerline striping on the roadway in Sutton would help

delineate the travel lanes for motorists.

Stopping Sight Distance

Stopping sight distance is the distance required for a vehicle traveling at or near the design speed

to stop before reaching a stationary object in its path. Sight distance measurements were recorded

at the two proposed site entrances on North Street. Based on the spot speed study performed,

design speed of 45 miles per hour southbound and 40 miles per hour northbound were selected.

At the proposed single-family housing site entrance on North Street, the stopping sight distance

measured was over 600 feet to the north and 375 feet to the south. This site entrance has an

approximate 8% downhill grade to the north and an approximate 6% uphill grade to the south.

Based on the design speed selected and the roadway grades, the stopping sight distance required

by the American Association of State Highway Transportation Officials (AASHTO) publication

-12-

A Policy on the Geometric Design of Highways and Streets, 2004 for a downhill grade of 6% is

333 feet, for an uphill grade of 9% is 320 feet, and for an uphill grade of 6% is 331 feet. The

stopping sight distances available in both directions exceed the AASHTO requirements.

At the proposed town house site entrance on North Street, the stopping sight distance measured

was 380 feet to the north and over 600 feet to the south. This site entrance has an approximate

2% uphill grade to the north and an approximate 4% downhill grade to the south. Based on the

design speed selected and the roadway grades, the stopping sight distance required by AASHTO

is 344 feet for a 3% uphill grade, and 378 feet for a 3% downhill grade. The available stopping

sight distance in both directions exceeds the AASHTO requirements.

Intersection Sight Distance

Intersection sight distance is the distance required for a vehicle on the major road to reduce speed

to no less than 70 percent of their initial speed due to entering traffic. Intersection sight distance

was measured at a minimum distance of 14.5 feet from the edge of the major road utilizing the

departure sight triangle in each direction

At the proposed single-family housing site entrance on North Street, the intersection sight

distance measured was over 460 feet for left turns from the site entrance and 600 feet for right

turns from the site entrance. Based on the design speed selected, the intersection sight distance

required by (AASHTO) is 500 feet for left turns from minor road and 430 feet right turn from

minor road. Based on the design speed selected the available intersection sight distance for the

left turn from the site entrance exceeds the AASHTO requirement. The right turn from the site

entrance the available sight distance does not meet the AASHTO requirements for design speed

of 45 mph due to roadway vertical alignment. The available intersection sigh distance for this

condition does, however, exceed the AASHTO requirement for a design speed of 40 mph, 2 mph

greater than the northbound 85th percentile speed.

At the proposed town house site entrance, the intersection sight distance measured was 600 feet

for left turns from the site entrance and over 455 feet for right turns from the site entrance. Based

on the design speed selected, the intersection sight distance required by (AASHTO) is 500 feet

-13-

for left turn from minor road and 430 feet right turn from minor road. Based on the design speed

selected, the available intersection sight distance for the left and right turns from the site entrance

exceeds the AASHTO requirements.

FUTURE CONDITIONS

The “no-build” condition is the future year condition that is expected regardless of the

construction of the North Village Residential Development. The development of the future “no-

build” condition involves the projection of existing traffic volumes over a specific time period

and the inclusion of anticipated trips from other planned or proposed developments in the study

area.

Background Growth

To determine the appropriate background growth within the vicinity of the project, the existing

traffic volumes were projected from 2007 to 2012 utilizing a 2.0% per year growth factor

calculated using Douglas MA Census data. The five-year period is the standard required by

MassHighway in their Guidelines for EIR/EIS Traffic Impact Assessments. This growth rate was

applied to the existing turning movements volumes to provide a year 2012 no-build turning

volumes.

Anticipated Development

The Town of Douglas and Sutton Planning Departments were contacted to determine projects

planned within the surrounding area that should be accounted for in the future no-build analysis.

No schedule development or roadway improvements are scheduled under near-term conditions;

thus, no major changes in traffic patterns are forecast.

The addition of the background growth and the 2007 existing traffic volumes results in the

formation of the future 2012 no-build traffic volumes. Figures 5 and 6 provide the future 2010

no-build volumes for the a.m. and p.m. peak hours.

-16-

2012 BUILD CONDITIONS

The future 2012 build condition represents the future 2012 no-build condition plus the traffic

expected to be generated by the proposed development. The future 2012 no-build peak hour a.m.

and p.m. traffic volumes are shown on Figures 7 and 8.

Trip Generation

The proposed North Village Development includes two separate parts: 105 residential

townhouses and 28 single family houses. Access for both parts of the development is proposed on

North Street. To determine the number of trips anticipated with the development, the Institute of

Transportation Engineers (ITE) Trip Generation, 7th Edition, was utilized. A summary of the

anticipated trips is presented in Table 2.

Trip generation for the proposed Residential Townhouses was completed with Land Use Code

230, Residential Condominium/Townhouse. The calculations were performed based on the

weekday a.m. and p.m. peak hours of adjacent street traffic. Using the rates provided the

proposed townhouse development is expected to generate 54 new trips, 9 entering and 45 exiting,

during the a.m. peak hour, and 63 new trips, 42 entering and 21 exiting, during the weekday p.m.

peak hour. The single-family houses were analyzed using Land Use Code 210, Single-Family

Detached Housing. Using the rates provided, the proposed single-family development is

expected to generate 29 new trips, 7 entering and 22 exiting, during the a.m. peak hour, and 34

new trips, 21 entering and 13 exiting, during the weekday p.m. peak hour.

Table 2: Trip Generation Summary

Time Period Residential Townhouse

Single-Family Housing

Total New Site-Generated Trips

Entering 9 7 16 Weekday AM Peak (vph) Exiting 45 22 64

Total 54 29 80

Entering 42 21 63 Weekday PM Peak (vph) Exiting 21 13 34

Total 63

34 97

Complete trip generation calculations are provided in Appendix C.

-17-

Trip Distribution

New trips anticipated to enter and exit the proposed development were distributed based on existing

travel patterns on the roadways adjacent to the development. Both entrances and exit to the

developments are located on North Street, By Evaluating the northbound and southbound existing

traffic volumes on North Street it was determine that during the a.m. peak hour, 68% of the traffic

will enter and exit the site northbound and 32% enter and exit the site southbound. During the

p.m. peak hour, 34% of the traffic will enter and exit the site northbound and 66% will enter and

exit southbound. Complete trip distribution calculations are provided in Appendix C.

CAPACITY ANALYSIS – EXISTING AND FUTURE BUILD CONDITIONS

Capacity analysis was completed for all study intersections for existing, future 2012 no-build, and

future 2012 build. Capacity analysis characterizes intersections based on their level of service

(LOS). LOS is a quality measure describing operational conditions within a traffic stream,

generally in terms of service measures such as speed, travel times, traffic interruptions, etc. Six

LOS are defined for each type of facility, from A to F, with A representing the best operating

conditions and F representing the worst operating conditions. The criteria for unsignalized

intersections is provided below.

Table 3: LOS Criteria for Unsignalized Intersections

Unsignalized Intersection

LOS Delay Time (sec/veh)

A 0-10

B > 10-15

C > 15-25

D > 25-35

E > 35-50

F > 50

Intersection operations and level of service were evaluated for the weekday a.m., afternoon, and

p.m. peak hours at the study area intersections using the latest version of the Highway Capacity

Software (HCS+).

-18-

Intersections

Capacity analysis for a.m. and p.m. peak hours was completed for the following intersections:

• North Street/Gilboa Street (Douglas, MA)

• North Street/Pond Street (Douglas, MA)

• North Street/Gilboa Court (Douglas, MA)

• North Street/Townhouse Site Entrance (Douglas, MA - Future Build Condition Only)

• North Street/Single-Family Housing Site Entrance (Douglas, MA – Future Build Condition

Only)

• Whitins Road/Hough Street w/Barnett Road (Sutton, MA)

Under existing conditions, the intersections of North Street with Pond Street, North Street with

Gilboa Court, and Whitins Road with Hough Road operate at LOS B or better during the a.m. and

p.m. peak hours. Under both the future no-build and future build 2012 conditions, the LOS at

these intersections remains a LOS B or better, with delay times less than 14 seconds per vehicle.

The analysis of the intersection of North Street and Gilboa Street presents a unique challenge due

to the unconventional configuration of the intersection. This intersection currently operates as a

3-way stop-controlled intersection, with the westbound approach operating unopposed. The

methodology of the Highway Capacity Manual does not address this unusual configuration;

therefore, the intersection could not be accurately modeled. To approximate the operation of this

location, the intersection was analyzed as a 4-way stop-controlled intersection with the

understanding that delays for the westbound approach would be erroneous. What this analysis

does reflect, however, is that the impact on the operation of the northbound, southbound, and

eastbound approaches as a result of the proposed development will be minimal.

Under existing conditions, during the a.m. peak hour, the North Street intersection with Gilboa

Street operates at an overall LOS C with approximately 16 seconds of delay per vehicle. Under the

future no-build 2012 conditions, the operation of the northbound approach decreases to LOS D,

with just over 28 seconds of delay per vehicle. The LOS of the other approaches remains

-19-

unchanged, as does the overall intersection LOS. The addition of the anticipated site traffic has no

impact on intersection LOS, and results in just over 23 seconds of delay per vehicle.

During the p.m. peak hour, the intersection of North Street and Gilboa Street currently operates at a

LOS F with approximately 59 seconds of delay per vehicle when modeled as a 4-way stop. The

northbound, southbound, and eastbound approaches to the intersection operate at LOS C or better,

with less than 17 seconds of delay. The westbound approach to the intersection operates at LOS F

with 92 seconds of delay per vehicle. The addition of future no-build 2012 traffic will increase

delay on all approaches. The northbound, southbound, and eastbound approaches to the intersection

will remain at LOS C or better, with less than 19 seconds of delay per vehicle. The westbound

approach continues to operate at LOS F with increased delay times. Under future build 2012

conditions, the LOS will remain unchanged after the addition of the site-generated traffic, with

delay increases of less than two seconds on the northbound, southbound, and eastbound approaches.

The intersections of the proposed development site entrances with North Street are expected to

operate at LOS A or better with less than 9 seconds of delay per vehicle under future 2012 build

conditions during both the a.m. and p.m. peak hours.

Capacity analysis results are provided in Appendix D and level of service tables are provided in

Appendix E.

-22-

CONCLUSIONS

The stopping sight distance for traffic exiting the development from both proposed site entrances

is adequate the selected design speed and the existing roadway grades. The available intersection

sight distance for the townhouse site entrance and the right turns out of the single-family housing

entrance exceed the AASHTO requirements. Intersection sight distance available for the left

turns from the single-family housing entrance does not meet the AASHTO requirement for the

selected design speed but it exceeds the requirement for the 85th percentile speed and the posted

speed limit.

Given the current travel speeds on North Street, it is recommended that intersection warning signs

be posted on the roadway in both directions in advance of the proposed site driveways. These

signs will warn motorists of the increased likelihood of entering traffic and potentially slow travel

speeds along the roadway. In addition, centerline striping on the roadway in Sutton would help

delineate the travel lanes for motorists.

The overall results of this traffic impact analysis indicate that the additional traffic anticipated

with the construction of the proposed North Village Residential Development will have minimal

impacts on the intersections within the study area. With the exception of the North Street/Gilboa

Street intersection, minimal changes in LOS and delay at the study area intersections can be

expected. The capacity analysis results for the North Street/Gilboa Street intersection do not

accurately represent existing or proposed conditions, as there is no available methodology to

analyze a 3-way stop controlled intersection. The volume of traffic expected to be added to this

intersection is minor, therefore, significant impacts to the intersection operations are not

anticipated. Changes in LOS and delay at the intersections are greater as a result of the

background traffic growth than as a result of the proposed development.