‘Y’ solution part of Green Mobility Challenge

November 25, 2011

The ‘Y’ solution above is part of the Green Mobility Challenge winning design by an Oak Hill team.

By Ann Fowler

Two Oak Hill roadways were the focus of a design challenge seeking innovative ways to build and maintain them. Highway engineers, planners and landscape architects were put to the test to provide a “green” facelift for the ‘Y,’ and create the 3-mile State Highway 45 Southwest (SH 45 SW) to connect Mopac with FM 1626.

The Central Texas Regional Mobility Authority (CTRMA) and the Texas Department of Transportation (TxDOT) partnered to host the Green Mobility Challenge. The judges for the final presentation included Texas Senator Kirk Watson; Janice Brown, Texas FHWA Division Administrator; Judge Bert Cobb, Hays County; Council Member Chris Riley, City of Austin; Rob Spillar, City of Austin Transportation Director; and Carlos Lopez, P.E. TxDOT Austin District Engineer.

The winner for the ‘Y’ project was truly a team effort, as it included Ricardo Zamarripa, Ken Schrock and Roland Gamble of the Oak Hill civil engineering firm LJA Engineering, Oak Hillian Aan Coleman and Marsha Jenkins of the landscape design firm Coleman and Associates, Carlos Swonke of the Lakeway environment planning and project management firm Blanton & Associates, and David Batts of the storm water quality specialists Construction EcoServices.

Features of the LJA team’s proposal included a regional park at the current HEB center site, a separate “Oak Hill Parkway” to serve a town center and the Austin Community College, and the relocation of Williamson Creek to allow U.S. 290 West to be widened at grade level.

The winning ideas for “the Manchaca Expressway” — SH 45 SW — came from AECOM Technology Corporation of Austin. The proposed features included a park along the entire roadway, intersections designed to eliminate traffic signals, green roadway shoulders and special roadway crossings to accommodate wildlife.

After reviewing the presentation for the ‘Y,’ “Recreating Community by Maximizing Connectivity,” Granada Hills resident David Richardson said, “The concepts proposed by LJA recognize many of the proposals floated in previous efforts hosted by UT and neighborhood planning.” Richardson is a former longtime board member of the Oak Hill Association of Neighborhoods (OHAN), and served as Chair for the Oak Hill Neighborhood Planning and Contact Team.

Steve Pustelnyk, the CTRMA director of communications, told the Gazette, “The environmental studies for the Oak Hill Expressway and the Manchaca Expressway are in the process of getting underway. In conjunction with those studies, the Mobility Authority recently hosted the Green Mobility Challenge, a competition to identify innovative ways that we might design, build, operate and maintain these projects in a more sensitive and sustainable way.”

Ricardo Zamarripa of LJA Engineering, told the Gazette, “We were excited by the challenge of competing against our peers in a competition that would encourage some of the best green ideas in the industry. We take pride in providing green options to traditional projects that improve sustainability, provide solutions for the community beyond mobility and controls or reduces costs.”

A parkway that parallels U.S. 290 West from State Highway 71 to FM 1826 would allow local access to Austin Community College, the West Park PUD and the Oak Hill Plaza. Locals had hoped such a roadway would be possible during discussions about the development of the West Park PUD at U.S. 290 West and FM 1826, but it would only come to fruition if all landowners agreed.

A porous pavement used on the U.S. 290 West thoroughfare could translate to less noise, according to the proposal, reducing traffic noise at the source. With the number of cars expected along the widened roadway, some residents had expressed concern that the noise from added traffic — and from an elevated roadway — would diminish their quality of life. The proposal suggests that a quieter pavement could save the cost of constructing walls used as noise barriers. In addition, this pavement significantly reduces splay and spray, making it safer for drivers in wet conditions.

Zamarripa said creating a redesign for the ‘Y’ was a natural for the people on the team. He explained, “It was an easy choice for our team as we have strong connections to Oak Hill and the ‘Y’ beyond our office being located in Oak Hill. Several members of our team have been involved with previous attempts to develop this project and are anxious too for it to succeed. Our staff also live, work and play in this area and are ready for the project to be successful.”

The LJA presentation pointed out that the original U.S. 290 West construction literally divided the community: “Oak Hill synergy was forever altered by the bifurcation created by the Highway.” The proposal suggests the “Oak Hillway” approach will reconnect the community, establishing both community support and economic sustainability.

“Gateways” at the intersections of Scenic Brook, FM 1826, Convict Hill Road, the ‘Y,’ William Cannon and Patton Ranch Road will provide “at grade” underpasses for pedestrians, bicyclists, transit and local traffic. Each gateway will be designed with a unique, Oak Hill name to help in location identification—at Scenic Brook: Oak Hill Springs; at FM 1826: “Oatmanville”; at Convict Hill Road: “Convict Hill”; at 290 and 71: “The ‘Y’”; at William Cannon: “Shiloh” and at Patton Ranch Road: “Williamson Creek”.

Moving Williamson Creek is not new, said the team in its presentation, as a portion of it was shifted during that original construction: “A section was moved as part of the original construction of 290 (formally known as State Highway 290); this relocated section has un-natural (straight/manmade) geometry and opportunistic and invasive vegetation.”

According to the proposal, moving the creek would allow highway main lanes to remain at grade level, resulting in a major cost savings. But local resident and Fix290 member Carol Cespedes is not convinced that shifting the creek is advisable. She said, “I am wary of plans for relocating and restoring the creek. I would like to have a third party opinion on this.”

Richardson said, “Much of this concept would be contingent upon federal approvals relocating the creek to accommodate U.S. 290 and local officials and staff recognizing this compelling need to fix this problem. Moving the creek would offer greater opportunities but would require condemnation of Freescale property and relocating their storm water detention ponds. This is not impossible — but challenging.”

Still, Richardson saw big benefits in moving the creek: “The upside is reduced impact on Williamson Creek. It has the added benefit of eliminating the third level direct connect at the ‘Y’ by merging 71 and 290 at Joe Tanner in the eastern segment of the road improvement. In so doing, this keeps 71 more of a local road through Oak Hill. ROW [right of way] alignment with a future [FM] 1826 extension needs to be included in the plan, but it has merits overall.”

Not all of the concepts in the winning presentations are a lock be adopted. Said Pustelnyk, “It is important to note that all reasonable and feasible ideas submitted as part of the Green Mobility Challenge will be on the table as we begin the environmental study. Some of these ideas may be great ideas while some could prove to be unpopular, unreasonable or unaffordable. The key thing I want to emphasize is that we are serious about studying a wide range of options this time and engaging the public extensively in the study process.”

Richardson noted that the proposal suggested turning the HEB center’s land into a park by incentivizing the landowner to redevelop at the new town center. He said, “This concept was explored extensively and dismissed as financially impractical. Short of condemnation, there is no way the owner will relinquish this property. Condemnation is too expensive and the City avoids it. Short of a partnership between the City and ACC, there is little opportunity to incentivize shifting existing commercial space at the HEB center to other locations in the town center further west.”

According to the proposal, the proposed park would protect the creek while providing “aesthetic relief” at the ‘Y.’ Richardson had an idea on how to finance the move of the current shopping center. He said, “An alternative might look to a mitigation strategy for the highway itself. Part of the toll revenue could be used to pay for moving the HEB commercial center to reduce run off from the HEB parking lot.”

The plan would preserve as many existing trees as possible, replacing those that are removed with multiple species of oak as a way to “re-oak” Oak Hill.

Areas upstream of intersections would be paved with Porous Friction Course for the initial treatment of water, which then runs across a grass filter strip and into a grass swale — a low tract of marshy land. In addition, a high performance biofiltration system would be used.

The Green Mobility Challenge was a win-win situation for Oak Hill. The first place winners of the Green Mobility Challenge were awarded $15,000, and the LJA team has plans for the money. Said Zamarripa, “We are donating the winnings to the Oak Hill fire victims. Our team has strong ties to the area and we understand the hardship the fire caused, so it made sense to take those winnings and do something positive in the community.”

As for the ‘Y,” Zamarripa concluded, “Oak Hill residents are ready for this project and we wanted to ensure that we are a part of the process that finally unifies the community and TxDOT to build this project.”