The state Highway & Transportation Department’s plan to widen Interstate 30 in Little Rock would push congestion and bottlenecking to new areas unless other roadways are widened, according to a presentation Wednesday by leaders at Metroplan.
Metroplan Executive Director Jim McKenzie and Central Arkansas Regional Transportation Study (CARTS) Director Casey Covington discussed their findings during a meeting of Metroplan’s Regional Planning Advisory Council.
More: See a copy of Wednesday’s presentation (PDF).
According to McKenzie, road widening and congestion can create an “endless cycle.” He said that when roads are widened to eliminate congestion, it encourages people to drive more and buy more cars, eventually leading to more congestion.
State Highway & Transportation Department officials recently unveiled a $600 million plan to widen the I-30 corridor, replacing the span over the Arkansas River and reworking on- and off-ramps downtown.
Critics have called those plans too costly and say they could harm the progress of downtown development in Little Rock and further divide portions of the city. Others have said improving arterial roads in Little Rock and North Little Rock would be more efficient and less costly and would result in less urban sprawl.
The Metroplan meeting followed a three-hour Little Rock City Board meeting on Tuesday where state transportation officials presented their plan and members of the public shared comments about the project. Highway officials have said they will work with cities about their concerns for the project.
In their study, McKenzie and Covington examined multiple highway construction scenarios to test and project congestion. The models project what would happen by 2040 under various highway changes and with no changes at all.
The models included an eight-lane central corridor, a 10-lane central corridor, and eight-lane freeways surrounding the area, including Interstate 630 to University Avenue and Interstate 40 to the north terminal.
“We need to expand Interstate 40 and I-630 as well,” Covington said. “We would have to do the associated widening all the way to Conway and Benton to avoid bottlenecking.”
The estimated costs of these variations ranged from $600 million for the most basic plan to $4.5 billion for the most extensive.
Covington analyzed whether the project would simply move congestion rather than eliminate it. He found that widening the I-30 in a small area would force traffic to merge back into fewer lanes and cause more congestion further from downtown.
“Widening Interstate 30 does little to improve the system travel time or average speed,” Covington said. “Improving the system performance will require a comprehensive approach.”
According to Covington’s presentation, the average vehicle speed in the current system is 45.2 miles per hour. He estimates that if there were no construction or changes, the average speed in the system would be 41.2 miles per hour by 2040.
But with an eight- to 10-lane network throughout the system, the regional vehicle miles traveled would increase by 4 percent by 2040 due to increased capacity of the roadway and more drivers in the system.
“Without corridor widening there will be severe congestion,” Covington said. “Widening I-30 moves congestion elsewhere unless improvements are done throughout the whole system.”
In order for the widening of I-30 to occur, the Metroplan board will have to make an exception to a provision created in 1995 and reconfirmed in December 2014 prohibiting roadways of more than six lanes. Metroplan has made one exception to the rule for part of I-630.
But McKenzie said that in order to create an eight- or 10-lane network throughout the system, the six-lane provision would need to be eliminated.
Metroplan’s Regional Planning Advisory Council is a voluntary, citizens council that Metroplan has charged with helping develop a long-range metropolitan plan, called Imagine Central Arkansas. According to the plan’s website, the regional plan aims to promote quality transportation, housing, health, environment and economic development.