Changes Proposed for Airline

2/12/04
Instead of widening parts of Airline Highway to six lanes, engineers want to unsnarl its traffic with an innovative intersection design.

The key to the concept is getting left-turn traffic out of the way of the intersections.  It does that by having the vehicles turn across oncoming traffic lanes on Airline several hundred yards before they reach those intersections.

The design is being used successfully at more that 40 intersections in Mexico and Europe, said Mike Bruce of ABMB traffic engineers.

“It’s out of the box, which is what people want these days,” said Bruce, whose company is pushing the idea.

Under a contract with the state and city-parish governments, ABMB has laid out the unusual traffic pattern to be installed at the Airline Highway intersection with Siegen Lane-Sherwood Forest Boulevard.  If the plan works like Bruce thinks it will, three more Airline Highway intersections will get the same treatment.

“We want to see if the public, No. 1, can handle it,” Bruce said Wednesday at a gathering of mayors, parish presidents and transportation officials from the greater Baton Rouge area.

The plan is difficult to describe; Bruce needed a 15-minute slideshow with animation to get his message across to the audience of politicians plagued by traffic complaints.  The design is called “Continuous Flow Intersections.”

The basic principle of the plan, Bruce explained, is to clear up the thing that’s most responsible for clogging busy intersections – left-turning traffic that must cross on-coming lanes.  Those turns require nearly all other traffic to stop.

The solution entails:

-Diverting left-turning cars off Airline onto new, dedicated turn lanes several hundred yards before the Siegen-Sherwood Forest intersection.

-Making the left-turn traffic cut across on-coming lanes of Airline well before the intersection.

-Sending those left-turning cars to the intersection in new lanes.  They would finish their left turns onto Sherwood Forest or Siegen at the same time that traffic going straight on Airline has a green light.

Traffic heading straight across Airline from Sherwood Forest of Siegen would be unaffected – except for possibly shorter waits at the light.

After watching several of Bruce’s animated diagrams, Mayor Bobby Simpson and several other officials expressed optimism.

“I’m kind of excited,” Simpson said.

The American Association of State Highway and Transportation Officials gave its 2002 national innovation award for the Maryland highway where a similar plan was implemented.  Bruce said that is the only American intersection where the design has come close to being fully installed.

“The original plan (there) was to build an overpass,” Bruce said.  “They don’t need the overpass anymore.”

He said construction on Airline should start in July and the intersection would be finished in 2005.  It would cost up to an estimated $3 million, with the federal government paying 80 percent, the state 20 percent and the city-parish paying some fees, Bruce said.

If the intersection design works at Siegen-Sherwood Forest and Airline, other “continuous flow intersections” would be built at Airline’s intersections with Goodwood Boulevard-Coursey Boulevard.  As with the Siegen-Sherwood Forest intersection, the new lanes would be added only to Airline, not the intersecting roads, because of right-of-way issues, Bruce said.

And if it works, Bruce said, the changes to all those intersections would replace a plan to widen Airline to six lanes between Cedarcrest Avenue and Connell’s Village Lane.  That widening project was estimated to cost $17 million and go out for bids next year.

He said using the unorthodox plan for intersections instead of widening the road to six lanes could save $5 million or more.

Roy Schmidt, DOTD administrator for the Baton Rouge area, said he is eager to see how the Siegen-Sherwood Forest intersection goes.

“We haven’t committed whole hog to the whole Airline project yet,” Schmidt said, “because we want to see one work.”