SH 146 Expansion Seeks to Reduce Congestion and Improve Travel Reliability
SH 146 Expansion in Houston: $201M Upgrades Aim to Make Hurricane Evacuations Faster and Safer
Just two days after Hurricane Harvey made landfall in Texas in 2017, parts of all 22 major freeways in the Houston metropolitan area were flooded. The result: nearly impossible travel conditions and significant challenges to rescue operations.
For many who live and work in the region, the devastation caused by this 1,000-year flood event is still fresh on their minds. But tragedy can provide valuable lessons to help protect others in the future. This includes prioritizing upgrades to evacuation routes so travelers have a reliable means of escape when hurricanes threaten coastline areas.
Currently, one area of focus is State Highway 146. This connection between Galveston and Houston serves as a major freight corridor as well as a hurricane evacuation route for thousands of residents. In February 2019, construction commenced to modernize approximately 4 miles of SH 146 in Harris and Galveston counties – between Red Bluff Road and Farm-to-Market 518, which is just north of State Highway 96. This five-year project will help to alleviate daily traffic congestion as well as facilitate safe passage for motorists during hurricane evacuations.
A Need for Better Infrastructure
SH 146 is currently a paved, four-lane highway with no sidewalks and all existing intersections are at-grade. An environmental assessment prepared in 2013 by the U.S. Department of Transportation cites deficiencies with the facility’s limited capacity, which has caused significant delays for many residents using the SH 146 corridor as a hurricane evacuation route.
Planned improvements consist of widening and restructuring the existing facility into a six- to 12-lane freeway with grade separations at major intersections and new access roads in selected locations. Crews are also tasked with widening an existing bridge over Clear Creek from four to six lanes and constructing a new four-lane express bridge in the same area, which will contain two northbound and two southbound lanes. Key project players include the Texas Department of Transportation (TxDOT) as owner and Webber, LLC as general contractor, with RS&H providing construction, engineering and inspection services.
It took years of negotiations and planning meetings to gain approval for this $201.8 million project, a top priority in part due to increasing regional populations. According to TxDOT’s latest projections, by 2048, nearly 83,000 motorists will traverse this section of SH 146 daily – an 80 percent increase over traffic counts in 2018.
“The travel needs of the community have outgrown the current infrastructure for both current and future needs,” says Will Bradley, a Senior Project Manager at Webber. “With this project, those visiting local attractions will be able to use the newly expanded bridge and frontage roads, while those passing through will be able to use the new express bridge to bypass the area, cutting down on local traffic congestion.”
In 2016, TxDOT moved forward with necessary right-of-way (ROW) acquisitions – a major hurdle, according to Public Information Officer Deidrea George, TxDOT Houston District. Land use along the project corridor consists primarily of railroad and commercial properties, the latter of which includes restaurants, banks, small retail centers, auto repair shops and gas stations. The three-year ROW acquisition process involved coordination with several local municipalities and purchasing dozens of local businesses.
A Multiphase Undertaking
The design-bid-build project has been divided into four phases. A total 3.7 miles of roadways and frontage roads are being built, with work on a new frontage road system through the cities of Seabrook and Kemah occurring throughout the project’s duration.
Phases 1 and 2 consist of widening the northbound and southbound lanes of the existing bridge over Clear Creek and building most of the new express bridge in the same area. Phase 3 picks up with reconstructing and elevating the existing SH 146 mainlanes, with grade separations at Repsdorph Road, NASA Road 1, Farm-to-Market 2094 and Farm-to-Market 518. Phase 4 will finish out the project with completion of the express bridge, which will be split into two separate structures to allow for a northbound exit ramp to Seabrook and a southbound exit ramp to Kemah.
Other project activities include: construction of a new stormwater drainage system; installation of new traffic signals and signs; improvements to an existing Computerized Transportation Management System; and aesthetic upgrades including landscaping and pavers, retaining wall patterns, lighting and decorative bridge medallions in coordination with the city of Seabrook.
Crews are utilizing heavy equipment such as Kobelco CK1100G Crawler Cranes for bridge work and a GOMACO GHP-2800 Slipform Concrete Paver for paving operations. Barges are being used as work platforms for any over-water construction.
Bridge Construction at Clear Lake
The project team has been collaborating closely with the U.S. Coast Guard to coordinate and perform construction within the Clear Lake area, home to one of the largest concentrations of recreational boats and marinas in the nation. Workers have already begun building the express bridge, which will be located west of and parallel to the Kemah-Seabrook Bridge.
Extending between Nasa Road 1 in Seabrook and Bel Road in Kemah, the new 2.4-mile-long structure will have about 80 feet of clearance above the water. Crews are currently focused on the bridge’s foundation, which will have over 700 drilled shafts.
Project team members are also overhauling the bridge spanning Clear Creek, an east-west channel that flows through Clear Lake and into Galveston Bay. Work has begun on the north and south ends of the waterway crossing and will finish in the middle. Once completed, the widened structure will have three travel lanes in each direction and contain a protected, 14-foot-wide multiuse path for pedestrian/bicycle traffic.
“One of the biggest challenges of this project is constructing the bridge over the active Clear Creek channel while allowing efficient use of the channel by the adjacent marinas,” says Bradley, adding that his team is focused on ensuring the safety of both construction personnel and boaters. A specialized traffic management system is being used on the water, which is continually monitored and adjusted based off feedback from the boating community.
A Potential Construction Approach
With over 1.2 million square feet of new bridge deck estimated for this project, construction using a traditional overhang system would require a significant time investment. To ease construction and speed completion of the bridge work, Webber is considering the use of precast overhangs.
“Webber plans to create a prototype panel to test the use of a precast overhang system. This will cut down on the time required for this initial bridge setup and potentially reduce the overall construction time,” Bradley says.
Precast overhangs are a newer method of construction for Webber. There are many factors to implementing this method successfully, including properly incorporating deck drains and light brackets into the precast operation. Also, the team must pay heed to ride quality on the final surface since the panels will be full depth and most will fall in the shoulder areas, Bradley adds.
Just a Few Years to Go
The entire project is slated for completed in February 2023. Communication will continue to be critical in advancing progress, minimizing impacts to the traveling public, and ensuring safety for all.
Bradley concludes: “This is a major construction endeavor in a high-profile area, being in close vicinity to the Kemah Boardwalk, NASA and the Clear Lake marinas. This requires constant communication between Webber, TxDOT and other governmental agencies, and other stakeholders in the area to ensure the safety of construction personnel and the traveling public.”