The following provides an overview of the Traffic Impact Study (TIS) process methodologies, and requirements. The outline highlights the exhibits (i.e., figures, tables, or other graphics) that are expected to be included in the TIS report.
1. Title Page
1.1. Development name
1.2. Location
1.3. Applicant’s name
1.4. Preparer’s name, address, phone number
1.5. Date of original report
1.6. Report revision date (when applicable)
2. Introduction
2.1. Purpose of report and study objectives (reference accepted Memorandum of Understanding; include in Appendix).
2.2. Proposed site development (zoning, land-use and anticipated size or quantity, location {Exhibit}, site plan {Exhibit}, phasing and timing).
2.3. Summary of revisions in the submittal (for revised reports only).
3. Area Conditions
3.1. Study area boundaries {Exhibit}.
3.2. Study area land uses (existing, anticipated future development).
3.3. Site accessibility (existing and future roadway system; document basic features to include jurisdiction, functional classification, pavement widths, lane usages, traffic control devices, speed limits, etc.).
3.4. TIS intersections (defined in the Memorandum of Understanding)
3.4.1 Lane usages and traffic control devices {Exhibit}.
3.4.2 Existing traffic volumes (AM and PM peak hour volumes {Exhibit} and other hours as requested {Exhibit}, include count information in Appendix ).
3.4.3 Sight distances (compare existing distances with established criteria).
3.4.4 Accident experience (if requested).
4. Traffic Volume Projections (for each horizon year)
4.1. Background traffic volumes (composed of existing volumes, accepted general growth rate for through traffic, and traffic generated by previously-approved new developments in the study area) {Exhibit}.
4.2. Site generated traffic volumes (trip rates, distribution, assignment) {Exhibit}.
4.3. Total traffic (background plus site) {Exhibit}. Exhibits must clearly show (1) Background, (2) Site, and (3) Total Traffic Volumes at each TIS intersection—for each study period and for each horizon year.
5. Traffic Operations
5.1. Capacity and level of service calculations for each TIS intersection (or applicable roadway element):
5.1.1. Existing conditions (i.e., current volumes on existing roadway system).
5.1.2. Horizon year background traffic conditions (i.e., projected background volumes on existing roadway system). If improvements/modifications to the existing roadway system are planned and programmed, Village staff will provide this information to the applicant and the improved roadway system will be used as a base for testing horizon year traffic conditions – as appropriate.
5.1.3. Horizon year total (i.e., non-site plus site) traffic volumes on existing (or planned and programmed) roadway system.
5.1.4. Horizon year total traffic volumes on improved/modified roadway system that mitigates the traffic impacts of the proposed development.
5.1.5. Produce a table {Exhibit} for each TIS intersection, study period, and study horizon year listing the level of service and delay (or v/c ratio) by (1) individual movement, (2) approach leg, and (3) overall for:
5.1.5.1. Existing conditions (Item 5.1.1 above).
5.1.5.2. Background conditions (Item 5.1.2 above).
5.1.5.3. Total conditions on existing roadway system (Item 5.1.3 above).
5.1.6. Through an iterative process, identify improvements/modifications that will mitigate the traffic impacts of the proposed development; expand the Exhibit table in 5.1.5. above to show how the improvements/modifications will mitigate the impacts by movement, approach leg, and overall. Table 1 provides an example of the requested information and format.
5.1.7. The minimum acceptable design level of service (LOS) in the Village is “C”. At intersections, analyses should show an overall LOS of “C” with no individual movement operating at less than “D” to be acceptable. If the analyses of background conditions show that conditions with only non-site traffic will result in a level of service below these criteria, the preparer should document this finding and ascertain the level of improvement needed to maintain at least the base level of service once site traffic is added. In other words, where unacceptable levels of service are calculated for background conditions (Item 5.1.2 above), the applicant is responsible for only maintaining the same level of service when site traffic is added to the roadway element.
5.1.8. Provide a scaled concept sketch {Exhibit} illustrating the improvements/modifications that properly mitigate the traffic impacts of the proposed development. Suggested improvements/modifications must be practical and acceptable to the appropriate agency/jurisdiction.
5.1.9. The computer printouts associated with all referenced capacity analyses must be included in the Appendix.
Table 1
SUMMARY OF INTERSECTION CAPACITY ANALYSES (EXAMPLE)
Intersection: SR 28 @ Woods Point Drive
Time Period: 5:00 – 6:00 PM
Year | 2004 | 2010 | 2010 | 2010 | Mitigation | |||||||
Volumes | Existing | Background | Total | Total | Measure | |||||||
Geometrics | Existing | Existing | Existing | Proposed | ||||||||
Delay (sec) | LOS | Delay (sec) | LOS | Delay (sec) | LOS | Delay (sec) | LOS | |||||
North Approach | - | - | ||||||||||
RT | - | - | 48.4 | D | 26.3 | C | ||||||
TH | - | - | 162.8 | F | 47.7 | D | ||||||
LT | - | - | 162.8 | F | 47.7 | D | ||||||
Approach | 91.2 | F | 34.3 | C | ||||||||
South Approach | ||||||||||||
RT | 25.7 | C | 33.9 | C | 83.9 | F | 40.9 | D | ||||
TH | 25.7 | C | 33.9 | C | 83.9 | F | 40.9 | D | ||||
LT | 25.7 | C | 33.9 | C | 83.9 | F | 40.9 | D | ||||
Approach | 25.7 | C | 33.9 | C | 83.9 | F | 40.9 | D | ||||
East Approach | ||||||||||||
RT | - | - | 122.3 | F | 20.1 | C | ||||||
TH | 5.7 | A | 5.9 | A | 122.3 | F | 20.1 | C | Add Through Lane | |||
LT | 4.4 | A | 4.9 | A | 4.8 | A | 10.4 | D | ||||
Approach | 5.7 | A | 5.9 | A | 121.9 | F | 20.0 | C | ||||
West Approach | ||||||||||||
RT | 10.1 | B | 18.3 | B | 4.6 | A | 11.7 | B | ||||
TH | 10.1 | B | 18.3 | B | 4.6 | A | 11.7 | B | ||||
LT | - | - | 205.8 | F | 46.4 | D | ||||||
Approach | 10.1 | B | 18.3 | B | 15.3 | B | 13.5 | B | ||||
Overall | 10.9 | B | 13.6 | B | 60.1 | E | 17.1 | B | ||||
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Timings optimized for year 2010 conditions
5.2. Traffic operations, safety, and control at TIS intersections:
5.2.1. Warrant analyses for left and/or right turn lanes; if warranted, define required lengths.
5.2.1.1. Left turn lanes should be provided at site driveways or at unsignalized intersections in accordance with the following conditions:
5.2.1.1.1. Per Graph 1, 2, or 3 (the left turn warrant charts) contained in the ODOT State Highway Access Management Manual, or
5.2.1.1.2. On major and minor arterial roadways with posted speed limits greater than 40 mph, or
5.2.1.1.3. On major collector roadways with posted speed limits greater than 40 mph and more than 10 left turning vehicles during a design hour.
5.2.1.1. Right turn lanes should be provided in accordance with Graphs 4, 5, 6, or 7 (the right turn warrant charts) contained in the ODOT State Highway Access Management Manual with the following exceptions:
5.2.1.2.1. Right turn lanes are not required for right turn volumes less than 10 vehicles during a design peak hour.
5.2.1.2.2. Right turn lanes are not required when there are less than 200 vehicles (during a design hour) in the approach or curb lane for roadways with more than one approach lane.
5.2.1.3. Left or right turn lanes may also be provided when deemed necessary for safety purposes by Village representatives.
5.2.1.4. The length of left and right turn lanes should be based on the criteria contained in the ODOT Location and Design Manual or, where appropriate, on the results of queuing analyses associated with the capacity calculations.
5.2.2. Queue analyses; describe critical queue lengths and provisions for proper storage lengths.
5.2.3. Sight distance analyses; define required sight distances and necessary measures to yield the appropriate distances.
5.2.4. Warrant analyses for the installation of traffic signals if such are recommended as a mitigating measure.
5.2.4.1. Signal Warrants as contained in the latest edition of the Ohio Manual of Traffic Control Devices (OMUTCD) shall be used for any formal request associated with the installation of a traffic signal.
5.2.4.2. If a signal is shown to be warranted in a horizon year, but is not warranted on opening day, estimates shall be made regarding the year that the signal may become warranted.
5.2.4.3. In general, the Village does not install a traffic signal unless the criteria specified in Warrant 1 (Eight-Hour Vehicular Volume) are met. Table 2 provides a general guideline associated with this warrant.
5.2.4.4. Any intersection that meets signal warrant thresholds must also be evaluated in terms of location and spacing based on the standards noted in the Village’s Access Management Standards, or the ODOT State Access Management Manual if applicable, for the access category assigned by the Village’s Thoroughfare Plan.
5.2.4.5. Signal warrant analyses may be conducted using projected traffic volumes to identify the potential need for the installation of traffic signals. However, traffic signals will not be installed unless: (1) the subject intersection is unquestionably projected to meet warrants on opening day of the development, or (2) actual counts at the intersection meet warrant thresholds.
Table 2
GENERAL GUIDELINE FOR TRAFFIC SIGNAL WARRANT 1
EIGHT-HOUR VEHICULAR VOLUME
Condition A: MINIMUM VEHICULAR VOLUME | |||
Number of Approach Lanes | Average Daily Traffic | ||
MAJOR | MINOR | MAJOR | MINOR |
1 | 1 | 8,300 | 5,000 |
2 or more | 1 | 10,000 | 5,000 |
2 or more | 2 or more | 10,000 | 6,700 |
1 | 2 or more | 8,300 | 6,700 |
Condition B: INTERRUPTION OF CONTINUOUS TRAFFIC | |||
Number of Approach Lanes | Average Daily Traffic | ||
MAJOR | MINOR | MAJOR | MINOR |
1 | 1 | 12,500 | 2,500 |
2 or more | 1 | 15,000 | 2,500 |
2 or more | 2 or more | 15,000 | 3,300 |
1 | 2 or more | 12,500 | 3,300 |
When the 85th percentile speed of major street traffic exceeds 40 mph in either an urban or rural area, or when the intersection lies within the built-up area of an isolated community having a population of less than 10,000, the warrants are 70% of the guidelines above.
5.2.5. Recommendations regarding speed limits.
5.2.6. Impact on current high-accident locations.
5.2.7. Accommodation of school zones, pedestrian and bicycle movements, transit system requirements, service and emergency vehicles, etc.
5.3. Site access circulation and parking:
5.3.1. On-site parking needs.
5.3.2. Ease of internal circulation.
5.3.3. On-site queuing provisions.
5.3.4. On-site traffic operations and control (as they may affect traffic operations on the external roadway system) {Exhibit}.
5.3.5. Design of site driveways to include pavement widths, lane usages, proposed median widths, traffic control devices, etc. {Exhibit}.
6. Findings and Recommendations
6.1. Site accessibility (site access and circulation plan).
6.2. Traffic impacts generated by the proposed development.
6.3. Recommended mitigating measures; i.e. improvements/modifications that properly mitigate the site-generated traffic impacts—to include phasing if appropriate.
6.4. Compliance with applicable local codes, MUTCD, location and design manuals, etc.
(Ord. 05-05. Passed 3-2-05.)