Alabama DOT Extends SR 158 to Connect to US 98 and Add Capacity
Smoothing the Curves: Alabama US 98/SR 158 Extension Projects Under Way to Improve Safety
Funding from the BP oil spill has allowed the Alabama Department of Transportation (ALDOT) to continue work on the $160 million 12-mile SR 158 extension to connect with the new U.S. 98 west of Mobile.
“It provides extra capacity, which will improve the safety,” says Don Powell, Operations Engineer for the Southwest region of ALDOT. “The existing U.S. 98 has a great many horizontal and vertical curves.”
Local residents had nicknamed the road “Bloody 98” due to the number of severe accidents on the route, which is heavily traveled by commercial vehicles and tourists from neighboring states on their way to Interstate 10 and Alabama’s beaches.
ALDOT began, in 2001, to construct new a four-lane extension of U.S. 98, but the state faced a setback in 2008, due to litigation associated with environmental concerns related to runoff of water and mud into wetlands and a threat to the city of Mobile’s drinking water supply. That led to redesigning the plans and purchasing more right of way in order for future projects to be more environmentally sensitive.
The department now has construction under way on the new two-lane road from Schillinger Road to the Mississippi State Line. The department broke the project into several segments to give local contractors an opportunity to participate in the construction as funding became available. All together, there will be seven separate projects. Two lanes are anticipated to be complete by 2022, which will complete the link from Mississippi to Interstate 65.
Eventually, SR 158 will have four lanes: two in each direction. However, funding remains uncertain for the additional lanes.
In addition to federal and state funding, $40 million in money from the $1 billion the state received after the BP oil spill in 2010 enabled the project to get started.
“Even during this time of reduced infrastructure funding, we were able to work with the local community to get this much needed project back started,” says Vince Calametti, ALDOT Southwest Region Engineer.
Projects Under Way: The Eastbound Bridge Extension
Two projects are under way, with one more to let this fall, expected to be about $33 million.
Tanner Construction of Laurel, Mississippi, is working on a $5.4 million extension of the eastbound bridge on U.S. 98 over Big Creek, which spans wetland areas. Work began on adding 1,400 linear feet of bridge in September 2017. Completion is expected this fall.
Big Creek supplies the drinking water supply for the city of Mobile.
“We went above and beyond for our erosion control,” Powell says.
Tony Cooper, Stormwater Coordinator for ALDOT’s Southwest region, adds, “The most challenging part of this project is balancing the construction progress with the continued implementation of best management practices and communication amongst project personnel.”
ALDOT is using a rock barrier for the entire work area, wetland seed mix and a drainage system that catches runoff, adds Sam Fountain, Construction Engineer with ALDOT.
“We are going to capture all of the water that falls on the bridge,” Powell says. “It will go into a piping system that goes into the median.”
If a hazardous spill occurs on the bridge, the system will contain it, and valves can be closed to prevent the material from entering the area’s potable water supply source.
While pouring the bridge deck, the contractor had to add hangers to hold the pipe. Otherwise, construction has been standard for a bridge.
Projects Under Way: SR 158
John G. Walton Construction Company of Mobile, Alabama, received the $16 million contract for building the 1.5 miles of SR 158 from east of Lott Road to Schillinger Road and started work in April. The project is expected to be complete in fall of 2019.
The entire job was modeled and crews are using GPS-guided dozers and other equipment, eliminating the need for staking, says Michael Gibson, Project Manager for Walton.
“It’s cutting down on surveying,” Gibson adds. “We’ve been able to build the project using GPS and have built some of the roadway to grade and placed asphalt on these sections.”
The project has some environmental challenges.
“We are doing everything we can to limit and minimize environmental impacts,” Powell says. “We’re installing sediment control basins and limiting activities the contractor can work on until they are stabilized.”
Sediment basins catch all of the stormwater before it leaves the jobsite. The water then is filtered before it can be released, Gibson says.
Additionally, ALDOT has called for level spreaders, 4-foot-tall, 100-foot-wide concrete walls, backed with rip rack. The water drains to it, and then the water cascades over a 100-foot width rather than 20-foot width.
“It spreads the water out over a larger area,” Powell explains.
The Walton crews also have encountered gopher tortoises on the site. Crews are required to inspect the site every morning, looking for gopher tortoises and black pine snakes. ALDOT has set traps and is relocating the tortoises when they are found. Gibson explains Walton has installed tortoise fencing to prevent burrowing and the animals coming onto the jobsite.
While these projects are under way, ALDOT has added more safety features to the existing highway, hoping to reduce accidents. For instance, in 2018, the department installed along the two-lane portions of the road centerline rumble stripes, groove patterns, which warn drivers they are crossing into the opposite lane. This is the first state/U.S. roadway in Alabama to have rumble striping in the center of the road.
This fall, ALDOT plans to let a contract for construction of eastbound SR 158 from east of Glenwood to west of Lott Road, which will open to two-way traffic. The westbound will be graded.
That project falls within the footprint of the drinking water supply.
“The first project gave us the ability to implement things that had never been done before and see how effective they were, before we were in the watershed,” Powell says. “Everything has worked wonderfully.”
Several environmental groups have visited the site and gave rave reviews, Powell adds.
In the years ahead, ALDOT plans to let four more projects. They include construction of a Lott Road overpass, a bridge on Glenwood Road, construction of a bridge on Wilmer-Georgetown Road over U.S. 98, and paving the original U.S. 98 project from the Mississippi Line to east of Glenwood Road. The entire project is expected to finish in about six years.
“We are glad to be working on these projects and getting some relief on U.S. 98,” says Powell.
- Owner: Alabama Department of Transportation
- Engineer: Alabama Department of Transportation
- Contractor, Eastbound Bridge Extension over Big Creek: Tanner Construction, Laurel, Mississippi
- Contractor, SR-158 Extension from East of Lott Road to Schillinger: John G. Walton Construction Company, Mobile, Alabama