§ 35-B122. Traffic Impact Analysis.

The TIA shall be signed and sealed by a licensed professional engineer with a demonstrated expertise in traffic engineering. The following information shall be provided in the following format:

(a)

All TIAs shall consist of the following. For study level TIAs, see subsection 35-B122(b).

(1)

Executive Summary.

A.

Site location.

B.

Development description.

C.

Principal findings.

D.

Conclusions.

E.

Recommendations.

(2)

Table of Contents.

(3)

Introduction.

A.

Project description.

B.

Project location.

C.

Purpose of project.

D.

Study procedure.

(4)

Existing Conditions.

A.

Project location map with site plan and study intersections identified.

B.

Roadway network.

i.

Street descriptions including number of lanes, posted speed limit, intersection geometry and traffic control at study intersections.

ii.

Transit service.

C.

Land use and zoning.

D.

Data collection/analysis periods - Weekday A.M. (7:00 a.m. to 9:00 a.m.), midday (11:00 a.m. to 1:00 p.m.), and P.M. (4:00 p.m. to 6:00 p.m.) periods should be used for traffic counting at intersections. However, Saturday peak hours should be included for retail uses or weekend generators. Analysis periods coinciding with the peak periods of special land uses where peak traffic typically occurs at non-traditional times, e.g., major sporting venues, schools, or other land uses, should also be included

E.

Existing peak hour traffic volumes - Existing traffic volumes are the turning movement volumes and ADT collected at the study intersections or along the roadways at the time the TIA is prepared, prior to the beginning of construction of the land development project. If data is collected during non-school periods, a seasonal adjustment factor should be applied. The factor should be based on actual traffic count data for non-school vs. school periods.

i.

Existing peak hour volumes and ADT figure.

(5)

"No Build" Condition.

A.

Future roadway/intersection improvement projects.

B.

Background peak hour volumes - Re-route background volumes if future roadway Improvement project would alter travel patterns.

i.

Annual growth factor calculation.

ii.

Modify traffic volumes to account for change in traffic patterns due to roadway projects, if appropriate.

iii.

Figure of background volumes in appendix.

C.

Other Project traffic.

i.

Identification and description of other nearby development projects. Provide copies of relevant pages from TIAs if appropriate. Figure of other project traffic to be included in appendix.

D.

No build peak hour volumes - Calculate "no build" peak hour volumes by combining other project volumes with background volumes.

i.

No build peak hour volumes figure.

(6)

Total Traffic Condition.

A.

Phasing plan for the development to include expected completion date.

B.

Project traffic.

i.

Trip generation calculation - including ITE land use codes, rates, peak hour entering and exiting volumes by land use, and daily volumes by land use.

ii.

Pass-by and/or internal trip calculations and reductions.

iii.

Modal trip adjustments.

iv.

Trip distribution by intersection.

v.

Trip distribution figure by land use (when different land uses have unique distributions).

vi.

Trip assignment by intersection.

vii.

Site generated peak hour entering and exiting volumes figure.

viii.

Future roadway network ADT and classification - Provide future ADT for proposed site roadways and identify classification, right-of-way, and lanes.

C.

Proposed site access locations - Identify proposed site access locations and proposed traffic control, configuration and identify sight distance limitations if appropriate.

(7)

Capacity Analysis.

A.

Capacity analysis will follow the principles established in the latest edition of the Transportation Research Board's Highway Capacity Manual (HCM), unless otherwise directed by the planning and development services director. Capacity will be reported in quantitative terms as expressed in the HCM and in terms of traffic level of service and measures of effectiveness (MOE) in seconds of delay. Capacity analysis worksheets shall be provided in the appendices and shall include level of service (LOS), delay, signal timing/phasing, volumes and geometry. An electronic copy of software analysis will also be provided.

B.

Existing condition intersection capacity analysis - Analysis of existing conditions at study intersections should be based on existing volumes, geometry, traffic control and signal timing/phasing.

C.

Signalized intersections - Provide overall level of service and intersection delay in seconds per vehicle for study intersections for all peak hours analyzed.

D.

Unsignalized intersections - Provide overall level of service, intersection delay and controlled approach delay for all-way stop-controlled intersections; provide approach level of service and delay for stop-controlled approaches at two-way stop-controlled intersections for all peak hours analyzed.

E.

Provide description of level of service results and identify problems.

F.

Future condition intersection capacity analysis - Analysis of no build and total traffic conditions at study intersections should be based on future volumes, geometry, traffic control, and signal timing/phasing. There should not be any changes to software input data for no build vs. total traffic condition with the exception of the project traffic volumes. All other variables (i.e. signal timing) should remain consistent unless identified and justified in text.

G.

Provide overall level of service and intersection delay in seconds per vehicle for study intersections and site access intersections for all peak hours analyzed for both no build and total traffic conditions.

H.

Unsignalized intersections - Provide overall level of service and intersection delay for study intersections, as defined under section 502(c)(3), and site access intersections for both no build and total traffic conditions; provide approach level of service and delay for all controlled approaches at study intersections and site access locations for all peak hours analyzed for both no build and total traffic conditions.

(8)

Identification of Impacts.

A.

Identify degradation in level of service results when comparing no build level of service to build level of service for all peak hours.

B.

Impacts that require mitigation improvements are identified based on section 35-502(c)(3)(b) of the UDC.

(9)

Mitigation Improvements.

A.

Identify improvements to mitigate impacts at study intersections.

B.

Provide level of service analysis results with proposed mitigation improvements in place.

C.

Provide construction cost estimate for proposed mitigation improvements.

(10)

Conclusions and Recommendations.

A.

A summary of level of service and appropriate measures of effectiveness (MOE) quantities of impacted facilities with and without mitigation measures

B.

Mitigation phasing plan if project has planned phasing.

(11)

Appendices. The following general categories and specific items should be considered for discussion in the traffic impact analysis:

A.

Traffic volumes:

i.

Current and historical daily and hourly volume counts.

ii.

Recent intersection turning movement counts (no older than six (6) months for undeveloped areas or one (1) year for fully developed areas).

iii.

Seasonal variations.

iv.

Projected volumes from previous studies or regional transportation plans.

B.

Land use:

i.

TIA threshold worksheet.

ii.

TIA scoping agreement.

iii.

Approved development projects and planned completion dates, densities, and land use types, if available or identified by the city (or county) during the scoping meeting.

iv.

Zoning in study area.

C.

Trip generation:

i.

Trip generation calculation.

ii.

Pass-by and/or internal trip calculations.

D.

Other transportation data:

i.

Origin-destination or additional trip distribution data.

ii.

Accident history adjacent to site and at nearby major intersections and major driveways if potential safety condition is identified by the city (or county) during the scoping meeting.

E.

Photographs:

i.

Photographs of approaches for each study intersection.

F.

Capacity analysis worksheets:

i.

Worksheet printouts showing volumes, geometry, level of service, signal timing/phasing, etc.

G.

Additional analysis worksheets:

i.

Worksheets used in analyses (i.e., signal warrant study, all-way stop warrant study, level of service and delay output, weaving and merge analysis, sight distance, queue length analysis, etc.).

(b)

Study level TIAs shall consist of the following:

(1)

Executive Summary.

A.

Site location.

B.

Development description.

C.

Principal findings.

D.

Conclusions.

E.

Recommendations.

(2)

Table of contents.

(3)

Introduction.

A.

Project description.

B.

Project location.

C.

Purpose of project.

D.

Study procedure.

(4)

Study Area Information.

A.

Boundaries of the study area.

B.

Existing major roadways and intersections serving the site in the study area.

C.

Planned major roadways and intersection improvements in the study area.

D.

Relevant information regarding planned improvements from the city, county, and/or TxDOT.

E.

Available existing and historical traffic count information at major roadway segments and intersections in the study area from the city, county, TxDOT, or previously completed traffic studies.

F.

Identification of the existing and future roadways and intersections that are relevant to the project and would likely be included in the future TIAs performed for individual plats.

(5)

Feasibility Study for Potential Land Uses.

A.

Determination of the potential land uses, densities, and resulting intensities that may be developed on the property (i.e. using existing topography and comparable properties to determine realistic floor-to-area ratios); and

B.

Determination of the resulting trip generation from the subject property for daily and peak hour trips.

(6)

Trip Distribution, Assignment, and Proposed Roadway Network.

A.

Develop a global trip distribution within the study area for the proposed development;

B.

Determine if trips will be generated by other developments or background growth that may impact the study area roadway network;

C.

Develop a conceptual roadway network to serve the proposed development;

D.

Assign the site generated traffic, background traffic, and/or neighboring development traffic to the study area roadway network;

E.

Determine the number of lanes along major roadway required to serve the proposed development;

F.

Analyze the adequacy of the proposed roadway network;

G.

Determine the amount of right-of-way required along major roadway segments and at major intersections to support the proposed development; and

H.

Identify approximate phase(s) or unit(s) where infrastructure improvements are to be implemented or restudied.

(7)

Conclusions and Recommendations.

A.

A summary of the conclusions and recommendations for the transportation network required to serve the proposed development.

B.

Identification of peak hour trip (PHT) levels that will trigger mitigation actions identified.

C.

A statement that each subsequent TIA submitted for the proposed development will be compared to the results of the Study Level TIA to determine if the overall roadway network remains adequate to serve the proposed development.

(Ord. No. 98697 § 1) (Ord. No. 2006-11-30-1333, § 2, 11-30-06) (Ord. No. 2009-05-21-0429, § 2, 5-21-09)(Ord. No. 2015-12-17-1077 , § 2, 12-17-15)

Editor's note

Ord. No. 2009-05-21-0429, adopted May 21, 2009, has an effective date of March 1, 2010.