Posted on Mon, Mar. 13, 2006 page 1A   http://www.macon.com/mld/macon/14084743.htm

Forest Hill project still raising questions about water runoff, traffic issues

By Travis Fain

TELEGRAPH STAFF WRITER

Stormwater runoff and traffic projections for Forest Hill Road have fluctuated widely, adding fuel to a long-standing fight about the road's planned widening.

The Macon City Council has joined what's been largely a grass-roots fight to have the project redesigned. Meanwhile, in June the Georgia Department of Transportation plans to start buying the land needed to turn two lanes into three- and four-lane sections.

Throw in an April meeting of the Macon Area Transportation Study Policy Committee - an influential body with some say about the project plan - and it's coming down to crunch time for the long-discussed, controversial road project.

The Telegraph has spent several weeks analyzing Forest Hill Road, particularly questions about how much runoff the $13 million project would create, how much traffic the new road will handle and whether a recent push to use roundabouts instead of signalized intersections has a chance to succeed.

THE DRAINAGE PROJECTIONS

Changes in the way water will be piped away from the road will keep increases in runoff to a minimum, according to a hydrological analysis and the Bibb County Engineering Department.

In fact, stormwater runoff will increase less than 0.4 percent, according to a report from Stantec, the engineering company handling the design.

That's in stark contrast to an initial and admittedly "very rough" Stantec prediction of a 30 percent increase in runoff, because of the increased asphalt that will be used for the project. As part of a brief October letter, the high number raised alarms, particularly for project critics who already thought the widening would increase flooding in surrounding neighborhoods.

"The intent of the letter was merely to inform all parties that a more in-depth study was warranted," Stantec engineers wrote in a response to Telegraph questions about the wide disparity in runoff predictions.

With that study done and changes in the storm sewer designs drawn up, "the miniscule increase in runoff will be channeled to a stream adequate to receive the runoff without experiencing harmful effects," Stantec reported.

Bibb County Engineer Ken Sheets agreed. So did Joe Wood, who manages the county's sales-tax financed roads improvement program for Moreland Altobelli, a private engineering firm that works closely with the county.

The percent change in predicted runoff is key because, if it's more than 1 percent, developers are required to include a retention or detention pond in their plans, according to city and county ordinances. But this is the first time a roads program project - as opposed to private construction - has been held to this standard, Sheets said.

"The ordinance, it's not for road projects," Sheets said. "It's really for development."

But the runoff change on Forest Hill was figured differently from the way it's figured for many private construction projects. The county and city ordinances, which use the same language, speak to runoff at the "site boundary." That means runoff is often figured at the edge of a construction site.

Stantec calculated the runoff change from Forest Hill Road based on the entire drainage basin, as opposed to the project area alone. This is a much larger area, leading to a smaller percentage increase.

Because Forest Hill Road is a long, linear project, it's appropriate to base the calculations on the basin as a whole, Sheets said. Stantec's written explanation states that local runoff policies have "some inconsistencies," but "the accepted engineering standard ... is to evaluate the drainage basin as a whole."

Bill Causey, who manages the city of Macon's engineering department, has pushed for the drainage ordinance to be enforced on the project since September. He feared erosion and flooding problems along Savage Creek - where runoff will be piped - would be worsened by the project. His requests led to Stantec's hydrological study.

Now, after weeks of back-and-forth over the right way to calculate runoff increases, Causey said he's satisfied with Stantec and the county's solutions, which include significant design changes such as velocity dissipaters and sewer pipes that will run at less than a 1 percent slope to slow runoff.

"They say they have (kept the runoff increase under 1 percent)," Causey said. "And they put that in writing."

[Read about the Grassy Swales solution to runoff - Swales ] 

THE TRAFFIC PROJECTIONS     see data chart comparisons   [ALSO READ MORE ABOUT GDOT DECEPTIONS]   [and more faulty estimates - faulty] 

Traffic projections, which help decide how wide a road should be, have varied by as much as 57 percent along Forest Hill road.

As with past arguments about such projections, project critics see this as evidence that Forest Hill Road will be overbuilt. Planners dismiss the differences as relatively unimportant.

There are three sets of figures: predictions for 2025 and 2030 done by the Macon-Bibb County Planning & Zoning Commission and Moreland Altobelli's predictions for 2028, which were used to plan the road project.

Though most of the projections show an increase in traffic between 2004 - the latest actual vehicle count along the road - and their prediction years, the 2030 numbers show traffic decreasing on some sections of the road. The 2030 numbers also are lower across the board than the 2025 and 2028 predictions.

Despite wide swings between the three sets of projections, Don Tussing, who calculated the 2025 and 2030 numbers for the planning & zoning commission, said there is "absolutely no reason to go back through and relook at these design numbers."

Tussing said he's comfortable with the 2028 numbers being used to guide the road's design and that they will prove more accurate than his 2030 predictions. That's because his calculations included an exaggerated vacancy rate in census figures, which depressed the 2030 numbers, he said. The more homes listed as vacant, the fewer new homes planners assume will be built. And each new home in an area equates to 10 trips a day, Tussing said.

Members of CAUTION Macon, a long-standing roads watchdog program, scoff at that logic.

"The road program has a long history of incredibly inflated projected traffic counts," CAUTION members said in an e-mailed statement to The Telegraph. "The Forest Hill Road design was based on such projections as well as a huge accident rate. CAUTION Macon has complained for years that these numbers are justified by neither the last 15 years of actual counts, any reasonable expectation of land usage in the vicinity, nor sound engineering procedure for analyzing traffic projections and accident rates."

CAUTION Macon members have an example in Houston Road, which was widened from two lanes to five in 2002. A 1999 consultant's report, which former Macon Mayor Jim Marshall recalled as key to the widening decision, predicted that between 20,600 and 24,100 vehicles a day would use the north end of Houston Road by 2025.

ROUNDABOUTS
http://www.macon-bibb.com/FHR/Roundabouts.htm

CAUTION Macon and the Macon City Council have asked planners to take a harder look at Forest Hill Road at roundabouts, which are essentially circles where vehicles yield to traffic already in the circle instead of waiting at a traffic light.

Traffic projections are key to the roundabouts issue because the DOT only considers roundabouts at intersections that handle 16,000 or fewer vehicles a day. But Michael Wallwork, an engineer and roundabouts expert, said they can handle about 25,000 cars a day. A roundabout in Daytona Beach, Fla., has handled 33,000 cars in a day, he said.

"There was a little backup," he said. "The backups I saw, you may get a six or eight, 10-car backup."

In Alachua County, Fla., planners are redesigning a two-lane road with nine roundabouts. The county's design manager, Bill Lecher, said that, in general, roundabouts can handle more than 20,000 vehicles a day.

But Pat Smeeton, Moreland Altobelli's head of environmental services and planning in Georgia, put the peak volume for roundabouts at about 10,000 cars a day. He said that, at peak hours, Forest Hill Road needs to serve 1,600 vehicles in an hour. That means multiple lanes and no roundabouts.

"Two-thousand cars can barely go in a single lane of a freeway in an hour ... let alone in a circle," Smeeton said.

Beyond DOT regulations and debate about roundabouts' effectiveness, there are other issues. They take up more space at intersections, Sheets said, even if less land would be needed overall if Forest Hill Road itself wasn't widened. American drivers aren't used to them. Wood, of Moreland Altobelli, said roundabouts don't allow for gaps in traffic that signalized intersections provide when there's a red light. That would make it harder for Forest Hill Road residents to get out of their driveways, he said.

Also, county officials have repeatedly said there's no money or time left to redesign Forest Hill Road. Changes this late would kill the project after almost 10 years of discussion, they have said.

The Macon City Council has asked the DOT to consider roundabouts at five Forest Hill Road intersections, so far without much success. The environmental assessment for the project - a required document that both the DOT and the U.S. Federal Highway Administration have to sign off on - already found that roundabouts aren't feasible for the project.

Still, some council members hope to force the issue by appealing to the Macon Area Transportation Study Policy Committee, an influential roads planning body.

Causey, who manages the city's engineering department, has suggested that a roundabout be installed at one intersection: Forest Hill Road and Lokchapee Drive. Traffic projections there range between 11,170 and 18,900 vehicles a day, depending on which numbers are used.

Said Sheets: "I don't think anybody here is saying (a roundabout) definitely won't work at (Lokchapee Drive). But we're 10 years into the project. ... It'd kill the project (to add a roundabout)."

To contact Travis Fain, call 744-4213 or e-mail tfain@macontel.com.