Leading engineering, design and planning consultancy Michael Baker International (MBI) has completed its environmental and design services work for a major road-widening project on US Highway 70 in Arkansas, with the enhanced corridor now opened to traffic.
The US$78.5m construction project for the Arkansas Department of Transportation (ARDOT) expanded the 18 mile-long (29km) stretch of US 70 between Interstate 30 and the city of Hot Springs, from two lanes to five, reconstructed four bridges, constructed 20 box culverts, and signalized a key intersection at SH 128 to improve safety for both local and through-traffic. During the initial construction of Highway 70 in 1956, additional right of way was purchased to accommodate the future construction of additional lanes; however, the right of way was never cleared or graded for this anticipated improvement. As traffic volume increased on Highway 70 through the Ouachita Mountains, so did the number and severity of accidents due in part to limited roadway width, narrow shoulders and clear zones, as well as limited sight distances due to rolling terrain, tight curves and dense forest.
The US 70 project was part of ARDOT’s US$1.8bn Connecting Arkansas Program (CAP), which comprises 36 projects to improve transportation connections on 19 corridors across the state. The US Highway 70 Project required the existing two lanes (one in each direction) to be converted to two travel lanes in each direction with improved safety conditions by straightening highway curves, flattening ditch slopes, eliminating the limited-length passing lanes, and providing a continuous center turn lane. MBI was tasked to correct portions of the roadway that did not meet current standards for horizontal and vertical alignments, while minimizing right-of-way impacts, environmental impacts and costs. The company recommended an approach to widen the roadway on both sides by generally following the original center-line, where possible, which helped to lower costs by using the existing pavement and embankment, while reducing the amount of cut and fill required through the rugged landscape. The construction work was completed by local company McGeorge Contracting.
“Widening Highway 70 presented a number of design challenges related to right of way and traffic maintenance that our design team successfully overcame to provide the highest quality improvements at a lower construction cost,” said Mike Stengel, vice president and office executive for Michael Baker’s Little Rock, office. “We are proud to have played such an integral role in this key project in central Arkansas, and we are excited about the improvements that this ARDOT project has made to both mobility and safety in this corridor.”