The Alabama Department of Transportation (ALDOT) decided it was time to update the warning system of the Bankhead Tunnel in Mobile, Alabama on Highway 90 after three trucks have become stuck at the tunnel’s entrance so far this year.
According to officials, last year there were five separate occurrences of trucks getting trapped and not able to make their way through. Clearance for the bridge is 12 feet.
David Johnson, the automated transportation center manager for ALDOT, told AL.com he believes the warning system in place is “very adequate” and that truck drivers “just need to pay attention.”
At both the east and westbound entrance, an electronic beam is transmitted across the width of the entrance, and if any vehicle taller than 12 feet breaks that beam, a big electronic warning sign and loud sirens are deployed.
In addition to flashing red lights and a “DO NOT ENTER” sign, oversized vehicles are hit by metal chains hanging down from the message board. At the eastbound entrance of the tunnel, Johnson said truck drivers have about 400 feet, or 7 seconds of response time after the warning signs.
“If the vehicle is going the posted speed limit, they should have enough time to respond before entering the tunnel,” Johnson told AL.com.
When a vehicle gets trapped, they usually have to be towed out. In addition, ALDOT’s Alabama Service and Assistance Program (A.S.A.P), mobile police and Mobile Fire-Rescue are all contacted if needed.
Because of an increase in incidents, PVC pipe was recently attached to the end of the chains as an update to the system. Now, any oversized truck will be struck by the pipes for an additional warning.
Check out this footage from a driver going through the tunnel. You’ll see the warning sign and chains at the entrance at around 23 seconds: