US 281 Environmental Impact Statement

Alternative 1 (Overpass/Expansion) Eliminated from Further Consideration

The overall intent of the Overpass/Expansion Alternative, as presented at Public Meeting #3 in April 2010, was to develop a "smaller footprint, lower cost" approach to addressing the project's Need and Purpose. This alternative proposed new grade separated intersections at Redland Road, Encino Rio, Evans Road, Stone Oak Parkway, Marshall Road, Wilderness Oaks, Overlook Parkway, Bulverde Road, and Borgfeld Drive.

Leroy Alloway (Alamo RMA) meets with an attendee during
Public Meeting #3 on April 29, 2010.

The Overpass/Expansion Alternative and the Elevated Expressway Alternative were presented with driveways and side streets colored red in numerous locations and noted that "Direct access may not by allowed as shown due to safety concerns. Further analysis is required to determine safe access solutions. Solutions include frontage roads, backage roads, and purchase of access rights." In addition to safe access, other measures of effectiveness like average peak period travel speed, average daily traffic, and peak period level of service were also lower than the Expressway and Elevated Expressway alternatives. In the months following the April 2010 public meeting the US 281 EIS Team worked to identify safe access solutions and improve mobility performance.

The US 281 EIS Team analyzed two variations of the original Overpass/Expansion Alternative. The original alternative was presented at Public Meeting #3 in April 2010. The first variation was presented to the Community Advisory Committee (CAC) and the Peer Technical Review Committee (PTRC) in October 2010. The second variation (February 2011) was presented to the CAC in February 2011, and to the PTRC in June 2011. Slide presentations made to all CAC and PTRC meetings are posted to the project web site, available for viewing at www.411on281.com/us281eis.

April 2010: This was the original version as presented at Public Meeting #3. This version of the Overpass/Expansion Alternative did not address safe access. It moved traffic much slower and at a lower Level of Service than the other Proposed Build Alternatives that were recommended for analysis in the Draft EIS. This alternative was refined by the US 281 EIS Team between April 2010 and October 2010.

October 2010: Design changes were made to the Overpass/Expansion Alternative between April 2010 and October 2010 in an effort to address safe access and improve mobility performance while retaining the original "smaller footprint, lower cost" intent of this alternative. Frontage roads were added between Loop 1604 and Stone Oak Parkway to provide safe access to the adjacent land uses. North of Stone Oak Parkway, traffic signals replaced originally proposed overpasses at Marshall Road, Wilderness Oaks, Overlook Parkway, Bulverde Road, and Borgfeld Drive, and an additional travel lane in each direction was added. Additionally, proposed right-of-way was expanded to include storm water management features. It should be noted here that the San Antonio-Bexar County Metropolitan Planning Organization travel demand model was modified in June 2010 which resulted in slightly different metrics, even for those alternatives that did not change.

The revised alternative still substantially underperformed the Expressway and Elevated Expressway Alternatives. In the northern section, due to the addition of traffic signals and more vehicle conflicts associated with sidestreets and driveways, the average peak period speed decreased to 12 mph as compared to 37-49 mph for the Expressway and Elevated Expressway Alternatives. Additionally, the Level of Service for the corridor was much lower for the Overpass/Expansion Alternative, and safe access concerns still remained north of Stone Oak Parkway.

February 2011: In order to mitigate safe access concerns and improve mobility in the northern section of US 281, additional changes were made to the October 2010 version. Overpasses were added to major intersections from Marshall Road to Borgfeld Drive in order to improve mobility along US 281. Short sections of discontinuous access roads and parallel driveways were included to provide safe access to the land uses along US 281. The US 281 EIS Team also investigated other strategies for addressing safe access, such as the acquisition of access rights and the construction of backage roads. These approaches were found to be prohibitively expensive (acquisition of access rights) and environmentally harmful (construction of backage roads).

US 281 EIS team presents to the CAC on February 16, 2011.

The addition of overpasses and discontinuous access roads north of Stone Oak Parkway to the Overpass/Expansion Alternative improved the measure of effectiveness, although this alternative still resulted in a relatively high percentage of centerline miles at Level of Service E/F compared to the Expressway and Elevated Expressway Alternatives. Also, in most cases, the discontinuous access roads required a circuitous route for accessing the adjacent land uses, in turn creating "choke points" where traffic would have to make sharp u-turns, pass through multiple signals, and/or quickly accelerate/decelerate to avoid conflicts with the faster moving main lane traffic.

In summary, during the effort to analyze safe access solutions it was determined that the safest and most economical access could be provided by the use of a frontage road in most locations. To incorporate frontage roads throughout the corridor would provide an alternative that was very similar to the Expressway Alternative - Non-toll. After extensive traffic and engineering analysis, the "smaller footprint, lower cost" approach was not found to adequately address the access and mobility needs of the project. This alternative was therefore eliminated from further consideration in the Draft EIS.