Transportation Impact Assessment Thorndike Place Arlington, Massachusetts Prepared for: Arlington Land Realty, LLC Cambridge, Massachusetts November 2020 Prepared by: 35 New England Business Center Drive Suite 140 Andover, MA 01810 TRANSPORTATION IMPACT ASSESSMENT THORNDIKE PLACE ARLINGTON, MASSACHUSETTS Prepared for: Arlington Land Realty, LLC 84 Sherman Street Cambridge, MA 02138 November 2020 Prepared by: VANASSE & ASSOCIATES, INC. Transportation Engineers & Planners 35 New England Business Center, Suite 140 Andover, MA 01810 (978) 474-8800 Copyright © 2020 by VAI All Rights Reserved CONTENTS EXECUTIVE SUMMARY .............................................................................................................. 1 INTRODUCTION ............................................................................................................................ 5 Study Methodology ............................................................................................................. 5 EXISTING CONDITIONS .............................................................................................................. 6 Geometry ............................................................................................................................. 6 Existing Traffic Volumes .................................................................................................... 9 Pedestrian and Bicycle Facilities ....................................................................................... 11 Thorndike Park .................................................................................................................. 11 Public Transportation ........................................................................................................ 11 Motor Vehicle Crash Data ................................................................................................. 12 FUTURE CONDITIONS ............................................................................................................... 15 Future Traffic Growth ....................................................................................................... 15 Project-Generated Traffic .................................................................................................. 17 Trip Distribution and Assignment ..................................................................................... 18 Future Traffic Volumes – Build Condition ....................................................................... 19 Parking Analysis................................................................................................................ 20 TRAFFIC OPERATIONS ANALYSIS ......................................................................................... 22 Methodology ..................................................................................................................... 22 Analysis Results ................................................................................................................ 25 G:\8451 Arlington, MA\Reports\TIA 1120 CONTENTS (CONTINUED) RECOMMENDATIONS AND CONCLUSIONS ......................................................................... 33 Recommendations ............................................................................................................. 33 Conclusions ....................................................................................................................... 34 G:\8451 Arlington, MA\Reports\TIA 1120 FIGURES No. Title 1 Site Location Map 2 Existing Intersection Lane Use, Travel Lane Width and Pedestrian Facilities 3 2020 Existing Weekday Morning Peak-Hour Traffic Volumes 4 2020 Existing Weekday Evening Peak-Hour Traffic Volumes 5 2027 No-Build Weekday Morning Peak-Hour Traffic Volumes 6 2027 No-Build Weekday Evening Peak-Hour Traffic Volumes 7 Trip Distribution Map 8 Site Generated Weekday Morning Peak-Hour Traffic Volumes 9 Site Generated Weekday Evening Peak-Hour Traffic Volumes 10 2027 Build Weekday Morning Peak-Hour Traffic Volumes 11 2027 Build Weekday Evening Peak-Hour Traffic Volumes G:\8451 Arlington, MA\Reports\TIA 1120 TABLES No. Title 1 2020 Baseline Roadway Traffic-Volume Summary 2 Public Transportation Services 3 Motor Vehicle Crash Data Summary 4 Vox on Two: 2019 Mode Split 5 Project Trip Generation Summary 6 Trip-Distribution Summary 7 Peak-Hour Traffic-Volume Increases 8 Parking Analysis 9 Level-of-Service Criteria for Unsignalized Intersections 10 Level-of-Service Criteria for Signalized Intersections 11 Unsignalized Intersection Capacity Analysis Summary 12 Signalized Intersection Capacity Analysis Summary G:\8451 Arlington, MA\Reports\TIA 1120 EXECUTIVE SUMMARY DESCRIPTION OF PROJECT Vanasse & Associates, Inc. (VAI) has prepared this Transportation Impact Assessment (TIA) to identify traffic impacts associated with a proposed Thorndike Place residential development to be located on the Mugar Parcel in Arlington, Massachusetts (the “Project”). The purpose of this TIA is to review existing and future traffic conditions in the vicinity of the site, determine the traffic impacts from the proposed Project at key intersections expected to experience increased traffic levels from the Project, and review the need for improvements to mitigate the Project’s traffic impact. PROPOSED PROJECT The site is bounded by Dorothy Road to the north, Burch Street to the east, and Route 2 to the west and south. The Project consists of constructing a building containing 176 residential units. Parking will be provided on-site for 239 vehicles. A parking garage below the units will provide 204 spaces while 8 spaces are provided in the courtyard. The remaining 27 spaces will be provided via a surface parking lot on-site. Approximately 144 bicycle parking spaces will be provided in the garage. Access to the site is proposed via one full-access driveway onto Dorothy Road at the intersection with Littlejohn Street. EXISTING CONDITIONS A comprehensive field inventory was conducted to collect existing roadway geometrics, operating characteristics, speed limits, and sight distances, as well as land use information. Traffic volumes were obtained for the intersections expected to receive the traffic impact from the Project. These are listed below: • Route 2 at Route 16 • Lake Street at Route 2 eastbound On/Off-ramps • Lake Street at Route 2 westbound On/Off -ramps • Lake Street at Wilson Avenue • Lake Street at Littlejohn Street • Lake Street at Homestead Road G:\8451 Arlington, MA\Reports\TIA 1120 1 • Lake Street at Burch Street and Alfred Road • Lake Street at Margaret Street and Lakehill Avenue • Lake Street at Brooks Avenue • Massachusetts Avenue at Lake Street 2020 BASELINE TRAFFIC VOLUMES CONDITIONS In order to develop 2020 Baseline traffic-volume conditions, the historic data obtained required adjustment for passage of time, while the new data collected required adjustment due to the effects of the COVID-19 pandemic. The counts conducted in 2020 were done in the month of September. Therefore, for practicality it was determined the other existing data should be corrected to September 2020 conditions. The 2014 counts were conducted in March 2014 and therefore were seasonally adjusted to September 2014 volumes using traffic count data from the Massachusetts Department of Transportation (MassDOT) permanent count station ID 40651 located on I-95 south of the ramp to Route 2 eastbound. Using the same permanent count station, the September 2014 volumes were grown to September 2016 volumes. The September 2016 volumes were subsequently grown to September 2019 using the same count station data. The 2019 data collected by VAI were conducted in May 2019 and were adjusted to September 2019 using the permanent count station information. The traffic volumes were then representative of September 2019 volumes. These volumes were then grown by 0.5 percent to raise them from 2019 to 2020 conditions. The next step was to develop a COVID-19 correction factor to apply to the counts conducted in September 2020. These factors were calculated comparing the August 2019 counts to the August 2020 counts from the permanent count station. Even with the COVID-19 correction factor, the counted September 2020 volumes were significantly lower than the derived September 2020 volumes. To correct for the difference, the networks were balanced upwards along Lake Street, and traffic volumes from specific developments that were occupied after 2014 but before 2020 were added to develop the 2020 Baseline traffic volumes. FUTURE CONDITIONS Traffic volumes within the study area were projected to 2027, which reflects a seven-year planning horizon consistent with State traffic study guidelines. These conditions incorporate traffic growth due to general background traffic increases as well as development projects currently being pro- posed/permitted or under construction and expected to generate traffic in the future. This condition is referred to as the No-Build condition. PROJECT-GENERATED TRAFFIC The Project is expected to generate 430 vehicle trips on an average weekday (two-way, 24-hour volume), with 27 vehicle trips (7 entering and 20 exiting) expected during the weekday morning peak hour. During the weekday evening peak hour, the Project is expected to generate 33 vehicle trips (20 entering and 13 exiting). The projected vehicle trips were distributed onto area roadways based on existing travel patterns and U.S. Census Journey-to-Work data for Arlington. Traffic-volume increases due to the Project