Month Year Traffic Impact Study Project Title

Month Year Traffic Impact Study Project Title

PROJECT TITLE

One sentence description of proposed project

TRAFFIC IMPACT STUDY

Prepared in Accordance With

Chapter 5 of the NYSDOT Highway Design Manual (HDM)

Prepared By:

[Regional Design Group] or [Consulting Firm]

[NYSDOT Region] or [Consultant Location]

Date (Month and Year)

PLACE P.E. STAMP

Note: It is a violation of law for any person, unless they are acting under the direction of a licensed professional engineer, architect, landscape architect, or land surveyor, to alter an item in any way. If an item bearing the stamp of a licensed professional is altered, the altering engineer, architect, landscape architect, or land surveyor shall stamp the document and include the notation "altered by" followed by their signature, the date of such alteration, and a specific description of the alteration.

This report is based on the NYSDOT TIS Shell revised on 5/16/2014.

Table of Contents

1.0 SUMMARY OF TRAFFIC IMPACTS 3

2.0 TRAVEL SPEEDS 3

3.0 CAPACITY ANALYSIS 3

3.1 Growth Rates 5

3.2 Existing Volumes 5

3.3 Projected Trip Generation 5

3.4 Internal Circulation & Parking 6

3.5 Traffic Control Device Data 6

3.6 Capacity Analysis for Existing Condition 6

3.7 Capacity Analysis for Proposed Condition 7

3.8 Mitigation Measures 7

4.0 CRASH ANALYSIS 8

4.1 Existing Crash Data 8

4.2 Analysis of Crash Data 8

4.3 Compare Rates to Accepted Values 9

4.4 Mitigation Measures 9

APPENDICIES 11

A Volume Report 11

B Existing Condition Capacity Analysis Output 12

C Proposed Condition Capacity Analysis Output 13

D Crash Analysis Diagrams/Tables (Major Commercial Only) 14

1.0 Summary of Traffic Impacts

Refer to Exhibits 5D-5 through 5D-7 in the NYSDOT Highway Design Manual, Chapter 5, Appendix D. The designer should reference the graph that best represents the existing highway configuration. The project will fall under one of the following conditions. Include one of the following statements:

A. [A capacity analysis was performed per NYSDOT Highway Design Manual Chapter 5. The following mitigation measures are recommended to maintain the existing no-build level of service and delays: ______. Refer to Section 3 of this report]

B. [The proposed development will maintain an acceptable Level of Service according to Section 3.0 of this report.]

The project will fall under one of the following conditions. Include one of the following statements:

C. [There are High Accident Locations (HAL’s) within 0.1 miles of the proposed driveway. A crash analysis was performed per Highway Design Manual Chapter 5. The following mitigation measures will be included to reduce the frequency and severity of crashes: ______.] Refer to Section 4 of this report.

D. [There are no High Accident Locations (HAL’s) within 0.1 miles of the proposed driveway. A crash analysis is not required.]

2.0 Travel Speeds

The posted speed limit and the off-peak 85th percentile speed determined based on NYSDOT Highway Design Manual Chapter 5, Section 5.2 are shown in the table below.

Identify the existing travel speeds on the segments of interest (85th percentile speeds are used for Work Zone Traffic Control and for capacity analysis). If multiple roads are being analyzed, present the data in a table. Show the:

(1) Existing Speed Limit

(2) Actual Operating Speed (from NYSDOT Traffic Data Viewer or a speed study)

https://www.dot.ny.gov/divisions/engineering/applications/traffic-data-viewer

Exhibit 1
Speed Data /
Street Name / Limits
(From – To) / Posted Speed / Actual Operating Speed /
SR 14 / Main Street to 5th Street / 55 mph / 52.4 mph
CR 72 / SR 14 to Jay Street / 45 mph / 49.8 mph

3.0 Capacity Analysis

A. [Traffic conditions at the proposed driveway fall within the L.O.S. “E or Worse” zone for urban highways; or the L.O.S. “D” or “E or Worse” zones for rural highways. A capacity analysis is required.]

B. [Traffic conditions at the proposed driveway fall within the L.O.S. “C or Better” or “D” zone for urban highways; or the L.O.S. “C or Better” zone for rural highways. Further capacity analysis is not required.] (Designer should omit Sections 3 of this report, and continue with Section 4)

Capacity Analysis Overview

Capacity analyses performed in this report are consistent with the most recent version of the Highway Capacity Manual (HCM). The software used to perform this analysis is [VISSIM, Synchro-Sim Traffic, HCS 2010, or Sidra].

The HCM quantifies the quality of traffic flow in terms of levels of service (LOS). There are six levels of service, with LOS A indicating very low levels of delays and LOS F indicating high levels of delays associated with congestion. These represent a qualitative measure of operational conditions within a traffic stream, and the perception of conditions by motorists and/or passengers. Levels of service and capacity for signalized intersections are calculated for each lane group (a lane group may be one or more movements), each intersection approach, and the intersection as a whole. The intersection level of service is merely a weighted average of the individual approaches and may not be considered a valid measure of the quality or acceptability of an intersection design since it can conceal poor operating conditions on individual approaches.

Levels of service at unsignalized intersections are only calculated for minor movements since the through movement on the major street is not affected by intersection traffic control. The level of service for signalized intersections and unsignalized intersections can be compared.

The level of service for freeway facilities is a measurement of density expressed as the number of passenger car equivalents/lane/mile. The corresponding level of service represents the congestion of the roadway.

LOS for Signalized Intersection

LOS by Volume-to-Capacity Ratio (v/c)
Control Delay (s/veh) / v/c ≤1.0 / v/c >1.0
≤10 / A / F
>10-20 / B / F
>20-35 / C / F
>35-55 / D / F
>55-80 / E / F
>80 / F / F

HCM 2010, Exhibit 18-4, p. 18-6

LOS for non-signalized Intersections

LOS by Volume-to-Capacity Ratio (v/c)a, b
Control Delay (s/veh) / v/c ≤1.0 / v/c >1.0
≤10 / A / F
>10-15 / B / F
>15-25 / C / F
>25-35 / D / F
>35-50 / E / F
>50 / F / F

NOTE: a, b For approaches and intersection-wide assessment, LOS is defined solely by control delay.

2-way stop control - HCM 2010, Exhibit 19-1, p. 19-2

a All way stop control - HCM 2010, Exhibit 20-2, p. 20-3

b Roundabout control - HCM 2010, Exhibit 21-1, p. 21-1

3.1 Growth Rates

State the traffic growth rates. This data is available from NYSDOT Data Services Bureau or the Regional Planning Group.

EXAMPLE: Growth rates for this project were as follows:

Interstate and ramps: 1.7% / year as per NYSDOT Data Services Bureau

All other roads: 2% per year per NYSDOT Region 3 Planning Group

3.2 Existing Traffic Counts and Volume Data as AADT/DHV

State if existing AADT information is available on the NYSDOT Traffic Data Viewer https://www.dot.ny.gov/divisions/engineering/applications/traffic-data-viewer, or from the Regional Traffic Office. Attach the volume report in Appendix A.

If existing AADT information is not available, describe the methods used to collect volume data. Counts should be taken on Tuesday – Thursday during the school season, excluding holiday weeks.

· Mainline counts

· Driveway counts for existing commercial driveways

· Turning counts at intersections (as needed)

Show the methodology to convert the hard counts into AADT/DHV. Daily and seasonal adjustment factors should be used and are available on the NYSDOT Highway Data Services Webpage https://www.dot.ny.gov/divisions/engineering/technical-services/highway-data-services

EXAMPLE: Traffic Volumes were obtained from the NYSDOT Traffic Data Viewer and no hard counts were taken. Existing volumes are shown in the table below:

Exhibit 3.2
Existing Traffic Volumes for Study Area (No Build)
STREET NAME / EXISTING
(2008) / ETC
(2010) / ETC+20
(2030) / ETC+30
(2040)
AADT / DHV / AADT / DHV / AADT / DHV / AADT / DHV
SR 14 / 5000 / 180 / 5200 / 180 / 7200 / 250 / 8200 / 290
CR 72 / 3000 / 110 / 3120 / 110 / 4320 / 150 / 4920 / 170

3.3 Projected Trip Generation

Explain the projected number of vehicle trips generated by the business with the proposed driveway. Analysis should include the peak hour for the state highway (e.g., 5:00 – 6:00 PM) and the peak hour for the business (which could occur on a night/weekend, not necessarily coinciding with the mainline peak hour)

· Passenger car trip generation

· Truck trip generation

EXAMPLE: The proposed commercial driveway is expected to handle 125 one-way passenger car trips in the peak hour of 5 p.m. to 6 p.m.. There are expected to be 5 one-way customer truck trips in the peak hour. The business anticipates two truck trips per day to deliver product, however these will be made at night during off-peak hours.

3.4 Internal Circulation, Parking, Deliveries

Identify the following attributes about the site. The designer should demonstrate that the site layout will not create negative effects at the entrance (for example: Drive thru queues that block the entrance, parking spaces where backing vehicles need to utilize the driveway entrance, loading docks where trucks must back out onto the state highway). For minor commercial driveways, a labeled plan view drawing will be appropriate. For major commercial driveways, additional documentation should be provided (e.g., Expected Traffic Counts, Queue Lengths, Delay)

· Number of parking spaces, percent capacity at peak times, and duration of stay

· Utilization of on-street parking (even if adequate parking exists on site)

· Entrances and exits for delivery vehicles

· Information about circulation of vehicles at the site (i.e. one-way driveways, drive-thru lanes, turn restrictions onto the mainline, etc)

EXAMPLE: The proposed commercial driveway leads to a parking area in front of the business with parking for 45 vehicles. It is expected that passenger cars will utilize the driveway entrance and park in the proposed lot. There is a concern that trucks utilizing the business will park on the shoulder of SR 14. Parked trucks would block sight distance for other vehicles exiting the proposed commercial driveway. It is recommended to install “NO STOPPING OR STANDING” signs along SR 14 in both directions for 200 ft in either direction to discourage this activity. At peak times the parking lot is expected to be at 80% capacity with an average 15-minute duration of stay. Delivery vehicles will utilize the south side of the parking lot at during overnight hours. There are no proposed restrictions on turning movements into or out of the driveway.

3.5 Traffic Control Device Data

Identify existing/proposed traffic control devices. If traffic signals are involved, a table should show information (provided by the Regional Traffic Office) identifying which approaches have detection and provide signal timing data.

EXAMPLE: There are no traffic lights within the study area. There is a flashing blinker at the stop controlled SR 14/CR 72 intersection. All other intersections and commercial driveways within the study area are stop controlled.

3.6 Capacity Analysis for Existing No-Build Condition

Provide a capacity analysis for the existing no-build condition. Validate the model by providing a check against accepted data. Identity the software used for the analysis. Include the output file from the software in Appendix B. For major commercial driveways the software input file shall be provided to NYSDOT in electronic format.

EXAMPLE: The no-build level of service calculations for streets within the study area were computed using HCS+ computer software. The output file from the HCS+ analysis is attached in Appendix B.

Exhibit 3.5 /
Existing and Future No-Build Highway Level of Service /
EASTBOUND /
Road / Limits / Existing 2008 / ETC1 2010 / ETC+20 2030 /
SR 14 / CR 72 to Main Street / B / B / B /
CR 72 / SR 14 to Ridge Road / A / A / B /
Proposed Intersection Level of Service /
Major Road / Minor Road / ETC1
2010 / ETC+20
2030 /
SR 14 / CR 72 / B / C /

3.7 Capacity Analysis for Proposed Build Condition

Provide a capacity analysis for the proposed build condition. For major commercial driveways an analysis must be provided at each signalized intersection adjacent to the proposed driveway(s). In addition, signals within ½ mile of the proposed development should be checked for operation if there is an expected increase in left turns at that intersection. Identity the software used for the analysis. Include the output file from the software in Appendix C. For major commercial driveways the software input file shall be provided to NYSDOT in electronic format.

EXAMPLE: The proposed build level of service calculations for streets within the study area were computed using HCS+ computer software. The output file from the HCS+ analysis is attached in Appendix C.

Exhibit 3.5 /
Future Build Highway Level of Service /
Road / Limits / Existing 2008 / ETC1 2010 / ETC+20 2030 /
SR 14 / CR 72 to Main Street / B / B / B /
CR 72 / SR 14 to Ridge Road / A / A / B /
Proposed Intersection Level of Service /
Major Road / Minor Road / ETC1
2010 / ETC+20
2030 /
SR 14 / Commercial Driveway / A / B /
SR 14 / CR 72 / B / C /

3.8 Mitigation Measures

Identify any proposed mitigation measures that will be required for the proposed build condition:

· Addition of turn lanes

· Installation or re-timing of traffic signals

· Signage or striping to prevent unwanted turning movements from the proposed driveway

· TDM (Travel Demand Management) and TSM (Transportation Systems Management) may be incorporated as mitigation measures in congested areas. See HDM Chapter 24 for additional guidance on mobility measures.

Validate the proposed mitigation measures by providing a check against accepted data (reduction in crash rates, improvement in capacity analysis, etc.)

EXAMPLE: The proposed two-lane commercial driveway will be installed along the east side of SR 14. Due to the anticipated volumes of left turning traffic from southbound SR 14 into the driveway, the state highway will be widened and a left turn lane added. The proposed driveway will be stop controlled. Adequate horizontal, vertical, and intersection sight distance exists to accommodate traffic entering from the proposed driveway to SR 14 from a stop controlled intersection.