§ 35-502. Traffic Impact Analysis and Roughly Proportionate Determination Study.

(a)

The following are the steps to be undertaken by the applicant and the City of San Antonio and/or Bexar County as part of the traffic impact analysis (TIA) and roughly proportionate determination study.

(1)

The applicant evaluates, using a trip analysis, what type of traffic impact analysis, if any, is required for the development application and submits such evaluation to the director for approval.

(2)

If a detailed traffic impact analysis is required, then the applicant shall undertake the following steps:

A.

Conduct a meeting with city public works and planning and development services staff to determine the scope of the traffic impact analysis. If the development is located outside the city limits, the county engineer's staff shall also be included;

B.

Complete the traffic impact analysis in accordance with this chapter;

C.

Identify mitigation improvements and thoroughfare plan implementation requirements from subsection 35-506(e)(8), if any, that are needed to support the development; and

D.

Identify the total approximate cost, including design, engineering and construction, to deliver the mitigation improvements identified in step (2)C., if any.

(3)

The applicant, using the approved methodology of the City of San Antonio, shall determine the probable maximum amount of mitigation improvements (measured in dollars) that may be attributable to the development.

(4)

The applicant shall compare the cost of the mitigation improvements determined in step 2d to the maximum amount of mitigation improvements identified in step 3.

A.

If the cost of the improvements identified in step 2d is less than or roughly equal to the maximum amount of mitigation improvements identified in step 3, then the mitigation improvements identified in the traffic impact analysis are said to be roughly proportionate to the impact of the development.

B.

If the cost of the improvements identified in step 2d is greater than the maximum amount of mitigation improvements identified in step 3, then the mitigation improvements identified in the traffic impact analysis must be limited by the city to an amount roughly equal to the costs identified in step 3.

(b)

Traffic Generation Reports.

(1)

Neither a traffic impact analysis nor a peak hour trip generation form is required as a result of a change in zoning district boundaries for the following applications:

A.

Commercial retrofits, traditional neighborhood developments or transit-oriented developments as specified in table 201-1 and subsection 206(e);

B.

Developments located in the "D" Downtown or "IDZ" Infill Development Zone zoning districts; or

C.

Where the existing zoning is temporary resulting from annexation and no building permit has been previously requested.

(2)

Trip Analysis. The property owner, or owner's agent, shall submit one (1) of the following three (3) types of reports listed below based on the number of peak hour trips (PHT) generated by the proposed development as determined from the most recent version of the ITE Trip Generation Manual when the property is part of a master development plan (MDP), planned unit development (PUD), plat, building permit, or is subject to an application to rezone. PHT analyzed may be the A.M., Midday, P.M., Saturday, and/or Sunday peak hours, based on the peak hour trip generation for that given day. Linear trip generation rates shall be used, except where the ITE Trip Generation Manual clearly indicates the use of regression equations better captures the trip generation estimates.

A.

Peak Hour Trip Generation Form and Turn Lane Assessment. The form shall be required for developments generating less than seventy-six (76) PHT (inbound and outbound peak hour trips) during its highest trip generating peak hour. The form shall be supplied by the property owner, or owner's agent, identifying the trip generation information specified in Appendix "B," subsection 35-B122(a)(6). A development may generate enough trips to require the installation of a turn lane without requiring the need for a traffic impact analysis, therefore the form supplied by the property owner, or owner's agent, shall also address the need for turn lanes, as described in subsection 35-502(d)(2).

B.

Study Level Traffic Impact Analysis (TIA). For MDPs or PUDs greater than five hundred (500) acres in gross size, the purpose of a study level TIA is summarized below. The study shall include the information specified in Appendix "B" subsection 35-B122(b) and shall be submitted to accompany the MDP and/or PUD for submission to the city, county, and/or TxDOT, as appropriate. Plats will be studied on an individual basis in accordance with TIA requirements.

i.

Review the existing transportation network to determine the general needs associated with the proposed development;

ii.

Identify planned transportation projects and roadway improvements in the area;

iii.

Project future trips generated by the proposed development;

iv.

Distribute and assign expected trips onto the study area roadway network generated by the proposed development;

v.

Recommend the transportation network required to accommodate the proposed development;

vi.

Define roadway hierarchies; and

vii.

Define right-of-way requirements for both roadway segments and intersections identified at the required TIA scoping meeting.

C.

Traffic Impact Analysis and Proportional Mitigation Determination Report. A traffic impact analysis (TIA) and a proportional mitigation determination report shall be required when the property is subject to master development planning, development permitting, or rezoning; and

i.

The proposed development generates seventy-six (76) PHT or more;

ii.

The change to an existing TIA or existing zoning results in an increase of at least seventy-six (76) PHT or ten (10) percent of the total PHT for the proposed development, whichever is greater;

iii.

(When a building permit submitted for the development is of an intensity at least ten (10) percent greater (in the number of PHT) than assumed in the previously completed TIA;

iv.

A previously completed TIA for the subject area was completed more than five (5) years prior to the submittal date of current application; or

v.

When the number of access points are reduced or relocated.

vi.

When a development generates less than seventy-six (76) PHT, the applicant shall fill out a peak hour trip generation form, and may perform a rough proportionate determination to determine potential right-of-way dedication and turn lane requirements, or may make the dedication as required by the code.

vii.

A traffic circulation study for renovation of existing schools (public, private) is required.

TIA Requirements. A TIA shall be performed by the property owner (or its agent) according to the scope and format established in Appendix "B," subsection 35-B122(a).

(c)

TIA Levels and Study Areas.

Table 502-1:
TIA Study Area

TIA Level	PHT	Study Area
STUDY LEVEL	N/A	Within limits of MDP and/or PUD and those major thoroughfares immediately surrounding the MDP and/or PUD.
1	76—250	All intersections of the proposed development with the adjacent roadway system and those roadways and intersections located outside of the proposed development where the number of inbound or outbound PHT at relevant intersections is at least 76 PHT, but in no case shall this include roadways or intersections greater than one and one-half (1.5) miles from the boundary of the proposed development (measured along the city's existing or proposed roadway network).
2	251—1,000
3	1,001 or more
Traffic Circulation Study	N/A	Within adjacent roadway system
Note: TIA levels are for fee purposes only.

 

(d)

Traffic Impact Analysis.

(1)

For all developments where a TIA is required, a TIA scoping meeting shall be required. The purpose of the scoping meeting shall be to establish the TIA requirements in accordance with generally accepted practice (as described in the most recent version of the ITE Recommended Practice Transportation Impact Analyses for Site Development ). During the scoping meeting, the following elements will be determined: type of study, study area, trip generation, trip distribution and assignment, time period(s) of analysis (e.g. A.M., P.M., Saturday), analysis scenarios (e.g. opening day, build out, build out plus five (5) years), and growth rate assumptions for background traffic. The TIA scoping meeting shall be attended by the engineer performing the TIA, the property owner, or owner's agent, city staff (from both public works and planning and development services), and county staff, if applicable.

(2)

In no case shall the amount of time between the existing traffic scenario and the next time period to be analyzed exceed seven (7) years. For projects where the time to build out exceeds seven (7) years, an interim phase that occurs prior to year seven (7) of the development shall be analyzed.

Figure 502-1 Trip Distribution Network Diagram

PHT will be distributed through the adjacent roadway network based on the trip distribution identified in the TIA scoping meeting. The PHT will be distributed to subsequent intersections until the minimum seventy-six (76) PHT or the one and one-half (1.5) mile maximum distance is reached.

(3)

The existing and projected levels of service for each analysis scenario for signalized intersections, controlled approaches of unsignalized intersections, and associated roadway segments within the study area shall be identified during the TIA scoping meeting. Unsignalized intersections include two-way stop controlled (TWSC) and all-way stop-controlled (AWSC) intersections identified within the study area.

A.

The appropriate Level of Service (LOS) (using Highway Capacity Manual (HCM) delay values in seconds per vehicle) shall be determined for each analysis. Each analysis shall, at a minimum, include the following scenarios: existing traffic, "no build" traffic (existing plus anticipated growth of existing traffic plus neighboring development activity), and projected total ("no build" plus site generated) traffic.

B.

Mitigation improvements for each intersection shall be identified, for each time period of analysis, (with a preliminary cost estimate to implement the improvements) to either maintain a minimum intersection level of service of C or, when the projected background traffic delay value measured in seconds per vehicle is already below level of service C, to maintain the projected background delay value within ten (10) percent of the projected background traffic delay for unsignalized intersections and to within twenty (20) percent of the projected background traffic delay for signalized intersections and roadway segments.

C.

For the controlled movements at two-way stop controlled intersections, the delay experienced for these side streets may operate at a level of service at or below C. If the controlled approach has already been widened to at least two (2) lanes for three-legged intersections (to accommodate dedicated left-turn and right-turn lanes) or to at least three (3) lanes for four-legged intersections (to accommodate dedicated left-turn, thru, and right-turn lanes) and the intersection does not meet warrants for the installation of a traffic signal (typically when the side street controlled approach volumes are at or below one hundred (100) to two hundred (200) PHT), a delay value at or below level of service C may be deemed acceptable due to the lack of available mitigation improvements.

D.

If no mitigation improvements are available based on the determination of both the applicant and the city, the intersection or roadway segment shall be deemed non-compliant and identified as such within the traffic impact analysis. Non-compliant intersections and roadway segments are those that have been fully constructed to their ultimate master planned configuration and no improvements could be implemented without significant right-of-way acquisition or grade separations.

(e)

Roadway Classification, Turn Lanes, and New Traffic Signal Construction.

(1)

Roadway Classification. The following vehicles per day (vpd) will provide clarification to the roadway classification system for streets within conventional subdivisions exclusive of traditional neighborhood developments (TND) as related to master development plans, plats, zoning and building permits:

A.

Local A Street: Function of roadway UDC 35-506 (Table 506-1: Functional Classification System Description) and Appendix "A" (Definitions). Daily traffic volumes shall range between five hundred (500) to one thousand (1,000) vehicles per day vpd.

B.

Local B Street: Function of roadway UDC 35-506 (Table 506-1: Functional Classification System Description) and Appendix A (Definitions). Daily traffic volumes range from one thousand (1,000) to four thousand (4,000) vpd (houses fronting) and four thousand (4,000) to eight thousand (8,000) vpd (no houses fronting).

C.

Collector: Function of roadway UDC 35-506 (Table 506-1: Functional Classification System Description) and Appendix "A" (Definitions). Daily traffic volumes shall range from eight thousand (8,000) to ten thousand (10,000) vpd.

D.

Secondary arterial shall follow UDC 35-506 (Transportation and Street Design) and the City of San Antonio Major Thoroughfare plan, Ord. No. 98282. Daily traffic volumes shall range from fourteen thousand (14,000) to sixteen thousand (16,000) vpd for a two-lane road and thirty thousand (30,000) to thirty-four thousand (34,000) vpd for a four-lane.

E.

Primary arterial shall follow UDC 35-506 (Transportation and Street Design) and the City of San Antonio Major Thoroughfare Plan, Ord. No. 98282. Daily traffic volumes shall range from fourteen thousand (14,000) to sixteen thousand (16,000) vpd for a two-lane road, thirty thousand (30,000) to thirty-four thousand (34,000) vpd for a four-lane and six (6) lanes for greater than forty-six thousand (46,000) vpd.

(2)

Turn Lane Requirements at Site Access Locations.

A.

The construction of turn lanes may be limited due to topographic conditions or the need to obtain right-of-way from adjacent property owners. The applicant must show that all reasonable efforts have been made to implement turn lanes when required by this chapter. This may include relocating driveways or roadways to allow for the construction of turn lanes and/or offers to purchase right-of-way from adjacent property owners.

B.

Right turn lanes shall be required:

i.

At all driveways or streets with a daily entering right-turn traffic volume of five hundred (500) vehicle trips or fifty (50) vehicle peak hour trips;

ii.

At street and driveway intersections in TxDOT right-of-way at the option of TxDOT; or

iii.

Where unsafe conditions such as limited sight distance, high travel speed, uneven grade, etc. may exist.

C.

Left turn lanes shall be required:

i.

At all median openings;

ii.

At all driveways or streets with an average daily entering left-turn traffic volume of five hundred (500) vehicle trips or fifty (50) vehicle peak hour trips if no median;

iii.

At street and driveway intersections in TxDOT right-of-way at the option of TxDOT; or

iv.

Where unsafe conditions such as limited sight distance, high speed, uneven grade, etc. may exist.

(f)

Mitigation Improvements and Roughly Proportionate Determination.

(1)

The purpose of the traffic impact analysis is to identify if any mitigation improvements are necessitated by and attributable to the proposed development. Required mitigation improvements by the city and/or county may include the following:

A.

Implementation of the major thoroughfare plan; including right-of-way dedication (right-of-way dedication value shall be determined using the most recent appraisal district land values) and/or construction in accordance with subsection 35-506(e)(8).

B.

Improvements identified in subsection 35-502(b)(2)A. peak hour trip generation form and turn lane assessment and subsection 35-502(c) traffic impact analysis.

C.

Identification of other improvements. The applicant shall propose improvement measures for the items listed in Table 502-2. Other improvements include, but are not limited to, pavement widening, turn lanes, median islands, access controls, curbs, sidewalks, traffic signalization, traffic signing, pavement markings, etc.

D.

Improvements inside the TxDOT right-of-way required by the city and/or county, including right-of-way dedication, as approved by TxDOT.

Table 502-2
Minimum Areas to be Addressed in Roughly Proportionate Determination

ROUGHLY PROPORTIONATE DETERMINATION ITEMS
Item	UDC Section
Right-of-way dedication for adjacent exterior streets	506(d)(1)
Improvements to substandard streets	506(d)(9)
Projecting streets	506(e)(2)
Right-of-way dedication and construction of designated major thoroughfare plan streets	506(e)(8)
Dedication of arterial	506(g)
Upgrade existing traffic signals	506(k)
New traffic signal construction	506(k)
Other improvements identified in the TIA	502(c)
Right-of-way dedication and construction of left and/or right turn lanes	502(d)(2)
School flashers, signage, markings, ramps, transit amenities (bus shelters, bus stop, transit station, transit center) traffic control calming features	506(t)(3)
Bicycle facilities	506(d)(4)

 

(2)

For all phased development projects, implementation of the mitigation improvements must be completed no later than the completion of the project phase for which the traffic impact analysis show that they are required. Plats for project phases subsequent to a phase for which a mitigation improvement is required may be approved only if the mitigation improvements are completed or bonded by the developer.

(3)

Following the identification of mitigation improvements and any other improvements necessitated by and attributable to the development, the applicant shall utilize the methodology developed and approved by the city to determine if the mitigation improvements identified are roughly proportionate to the impact of the proposed development.

A.

At the conclusion of the TIA, the applicant will summarize all of the mitigation improvements identified in the TIA and the approximate total cost of all mitigation improvements including design, engineering and construction. Mitigation improvements that only serve the proposed development (such as site plan related recommendations and traffic signals that only serve the proposed development) that provide minimal to no benefits to the study area roadway network shall not be included in the cost of the mitigation improvements (when compared to the maximum amount of improvements attributable to the proposed development). Half credit will be given for right or left turn lanes into the development and for acceleration lanes out of the development.

B.

The applicant will utilize the approved methodology made available by the city to determine the maximum amount of improvements (measured in dollars) that may be attributable to the proposed development.

C.

The applicant shall then compare the cost of the mitigation improvements to the maximum probable amount of improvements that may be attributable to the development.

i.

If the cost of the mitigation improvements is less than or equal to the maximum amount of improvements that may be attributable to the development, then the mitigation improvements identified in the traffic impact analysis are said to be roughly proportionate to the impact of the development.

ii.

If the cost of the mitigation improvements is greater than the maximum amount of improvements that may be attributable to the development, then the mitigation improvements identified in the traffic impact analysis are limited to an amount roughly equal to the maximum amount of improvements that may be attributable to the development.

D.

The methodology utilized by the city shall be as follows. The maximum amount of improvements attributable to a development is roughly proportional to the demand created by a development. This value shall be determined (measured in dollars) by multiplying the following values together:

i.

Intensity of the development (using independent variable identified in the ITE Trip Generation Manual, e.g. number of dwelling units, number of one thousand (1,000) square feet of leasable floor area, etc.);

ii.

Number of vehicles—the peak hour trip generation rate for the applicable peak hour (from the most current version of the ITE Trip Generation Manual Information);

iii.

Length of the trip—the anticipated trip length to/from the development on the city's thoroughfare network (a minimum value of 1.0 miles and a maximum value of 1.5 miles shall apply); and

iv.

Cost per vehicle-mile—the average cost per vehicle-mile for the City of San Antonio to deliver a typical roadway capacity improvement project based upon the latest Average Unit Price List posted on the city website by the director of capital improvements management services (CIMS) department. The Average Unit Price List shall be reviewed by the Director of CIMS on a regular basis to ensure the Average Unit Price List is consistent with current construction costs.

E.

The methodology shall be reviewed by the director on a regular basis to ensure the methodology is consistent with current construction costs and engineering criteria.

F.

Projects within a valid master development plan or planned unit development where mitigation improvements have been previously constructed at the cost of the applicant shall receive credit for these improvements. The credit for improvements shall be determined using the cost of the improvements at the time they were constructed. This value shall be included with the total cost of the mitigation improvements required to serve the development. The land uses previously constructed or planned for shall also be included in the calculation of the maximum probable amount of improvements that may be attributable to the development.

(g)

Limitations on Traffic Impact Mitigation. Limitations on traffic impact mitigation requirements are as follows:

(1)

Improvements that have been planned and funded through a capital improvement project that exceed the proposed mitigation measures recommended in the TIA are not required. The capital improvement must be planned to be awarded to a contractor for construction within one (1) year following the completion of the project phase requiring the improvement to be considered as a mitigation improvement.

(2)

Requirements for mitigation for city sponsored land development projects located inside Interstate Highway 410 will be considered on a case-by-case basis and may be waived by the city council.

(h)

Exemptions. The city finds and determines that certain factors, such as interconnected street systems, mixed uses, and the availability of pedestrian facilities, can result in fewer trips than isolated, low-density subdivisions. Certain development patterns produce fewer trips and shorter trips than developments subject to conventional zoning or located on the fringe of the metropolitan area. The city hereby finds that traffic patterns and infrastructure within its urban core are established, and that there is a strong public policy to encourage reinvestment in the city's downtown areas. Further, the city hereby finds that there is a strong public policy to encourage infill development and that there is little opportunity to expand transportation capacity in many infill areas without destroying the city's historic built environment. Accordingly, the following are exempt from the provisions of this section:

(1)

Applications for development approval within the "D" Downtown district.

(2)

Any development within an "IDZ" infill Development Zone.

(3)

Any Traditional Neighborhood Development (TND) or any Transit-Oriented Development (TOD).

(Ord. No. 2006-11-30-1333, § 2, 11-30-06) (Ord. No. 2009-05-21-0429, § 2, 5-21-09) (Ord. No. 2010-11-18-0985, § 2, 11-18-10; 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.