Managing traffic flow

Popular Baton Rouge road widened to five lanes

By Angelle Bergeron

It's certainly not unusual for highway construction projects to affect traffic flow.

But since Barber Bros. Contracting Co. of Baton Rouge began the $17.4 million widening of Old Hammond Highway in Baton Rouge from Airline Highway to Boulevard de Province last June, traffic on the well-traveled thoroughfare has actually decreased, said Clay Hollowell, project engineer for the Louisiana Department of Transportation and Development.

"Traffic is nowhere near as bad as it was at the beginning," Hollowell said. He assumes motorists must be using alternate routes to avoid construction because the area has been consistently congested for some time.

In 1999, when DOTD completed designs to expand the almost 2-mi. stretch of Old Hammond Highway from two lanes to five, the average daily traffic was estimated to be 18,783.

"It's probably more than that now," Hollowell said. Comparatively, most of the state's two-lane rural roads average in the neighborhood of 5,000 to 10,000 motorists per day.

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Although Hollowell (who recently transferred from a rural district) said he isn't quite sure what the ADT (Average Daily Traffic) for a two-lane road in Baton Rouge would be, it's safe to say the traffic levels on Old Hammond Highway are high.

"A lot of sections on I-12 only have 25,000 ADT, and that's a four-lane interstate," Hollowell said.

By January 2006, motorists will have a little more room to spread out when the two-lane asphalt highway is widened to five lanes of finished concrete.

By the end of May, Barber Bros. >> expects to complete the two outside lanes, which were constructed immediately adjacent to the existing asphalt highway.

"We left the old road intact while we built the outside lanes so it wouldn't impact traffic flow," said Ronnie Falgout, construction manager for Baton Rouge-based Barber Bros.

All of the utilities were relocated before Barber began installing catch drains and subsurface drainage to replace the open ditches that hugged the edges of the old asphalt road.

"Then we did the dirt work, excavating where the outside lanes would be," Falgout said. "We cut lines in the subgrade, installed a geotextile fabric, put limestone base course on top of that and then placed 11in. of concrete."

Traffic continues to pose the biggest challenge on the project, Falgout said.

"The new road is quite a bit lower and in some spots it's probably a 2- or 3-ft. drop," he said. The differential is most substantial in areas where the contractor has taken the outside lanes down to the dirt.

While the old roadbed was built up to run off into the adjacent open canals, the new road is lower so that water will flow from the surrounding business and residential areas into the new catch basins and subsurface drain system.

"It was designed that way so it would go there instead of onto everybody's property," Hollowell said.

Delineators have been placed along the length of the work area to define the edge of the road, Falgout said, but the risk of vehicles slipping off the edge of the roadbed poses as great a safety hazard to Barber workers as to motorists.

The difference in elevation also makes it difficult to slipform the new concrete roadbed while maintaining access to driveways, Falgout said.

"It takes a lot of coordination with each individual business," he said. "We'll pour new concrete with the slipform up to the driveways, and leave a gap so that they can get into their home or business."

The contractor has been making temporary ramps at the entrances to business parking lots and residential driveways.

"We do it with traffic maintenance aggregate, recycled asphalt, which looks like black gravel," Falgout said. "Then we'll come back later, when it is convenient for the residents and merchants, and finish with the concrete. It makes the paving pretty difficult because you just can't go through and put in concrete >> continuously."

The drop from the roadway to drives won't be as substantial once the concrete is in place, he added.

"By the time we add 10 in. of limestone and 11 in. of concrete, it will bring the height up pretty close (to the roadbed)," he said.

Another challenge of the job was relocating some utility lines and catch basins.

"Some of those lines no one knew even existed, but we found them as we worked," Hollowell said.

Barber Bros. has set up a staging area in a yard off Old Hammond Highway near Sherwood Forest Boulevard and is running two concrete plants, Falgout said.

"It's more cost effective for us to produce our own concrete and a lot easier for us to set up," he said. "If you are relying on ready mix companies, sometimes it's hard to get it when you want it."

The on-site plants also make it easier for the contractor to schedule pours.

"When we are using the slipform paver, it takes a lot to feed it," Falgout said. "After the main stretch sets for about a week, then we've got to go back and fill in all of the gaps (for driveways), and you want to have enough material when you're ready to go."

Although the close proximity of the staging area has provided easy access for the contractor, some nearby businesses have grumbled a bit, Hollowell said.

"It's in a tight area," he added. "We're using every bit of the right of way and we're using all the room to work."

DOTD has plans for another widening project on Old Hammond Highway from Boulevard de Province to Millerville Road. The contract will be let later this year.

Useful Source:

For updates on the Old Hammond Highway project, go to:
http://www.dotd.state.la.us/construction/baton.html