Work to build Jefferson County’s first Diverging Diamond Interchange is reaching a significant milestone. The project will transform Exit 104 on I-59/20 at McAshan Drive in McCalla.
Over the last few weeks, the project’s new bridge the contractor began installing in late February passed inspection. The new span will run parallel with the existing McAshan Drive bridge to handle the new DDI configuration.
Final concrete work remains over the next few months for the lanes leading into and out of the upgraded interchange. Crews are also putting finishing touches on new concrete ramps needed for the high volume of truck traffic and expected continued growth in the area.
Once complete, McAshan Drive will become Alabama’s second Diverging Diamond Interchange.
Drivers can expect to enjoy a more efficient interchange since it eliminates a left turning movement to cross traffic. As drivers approach one side of the bridge, the design will allow traffic to gently transition from the right side to the left and then back again at the other end of the bridge.
Federal Highway Administration research shows DDI’s are more cost effective, efficient and safe.
- Reduce construction costs by up to 75 percent
- Lower vehicle conflict points by up to 50 percent
- Bump traffic flow efficiency by as much as 30 percent
Temporary lane closures will continue throughout the project. The McAshan Drive DDI should be open to traffic this fall.
Additional DDI’s are planned for the intersections of I-65 at Lakeshore Drive in Homewood and the future Exit 9 on I-459 in Hoover.
