Not long after two summers of construction on Interstate 471, there could be even more major changes coming to Campbell County's primary highway.
A $1.85 billion widening project is ranked as one of the Kentucky Transportation Cabinet's top 10 preliminary recommendations for upcoming road work, out of a list of 70 proposed projects. The cabinet will make its final transportation plan recommendations later this year, to be sent to lawmakers in the General Assembly for approval.
The Kentucky General Assembly considers its transportation budget each legislative session, planning for projects in a six-year cycle.
The project is meant to add lanes to I-471 in order to decrease congestion between the Ohio state line -- located on the Daniel Carter Beard Bridge -- and the highway's southern terminus at U.S. 27 in Highland Heights.
This work would differ from the previous "Revive the Drive" road rehabilitation initiative launched by the transportation cabinet in 2012, in that this would be a lane-adding effort versus a simpler re-paving project, according to spokesperson Nancy Wood.
"A project of this magnitude would probably be designed and constructed in several parts," Wood told WCPO. "Planning, environmental impacts, traffic analysis, and right-of-way costs will help determine the overall project."
Wood also said construction probably wouldn't begin sooner than at least four years after its approval, given the extensive studies that a project of this magnitude would require.
"A project to add lanes impacts every interchange, and interchange modification studies would also have to be concluded before a project could move forward," she said.
As far as work on the bridge, Wood said designers were still determining whether it would be necessary, but, "there is a strong possibility some type of work on the Daniel Carter Beard Bridge would be included with this project."
The project, though, would create another case study in the debate over whether or not added lanes actually decrease congestion.
As WCPO has previously reported, the jury is still out on whether road-widening helps or hurts. WIRED magazine's Adam Mann made an argument for the apparent illogic behind road widening, using an economics term:
"The concept is called induced demand, which is economist-speak for when increasing the supply of something (like roads) makes people want that thing even more. Though some traffic engineers made note of this phenomenon at least as early as the 1960s, it is only in recent years that social scientists have collected enough data to show how this happens pretty much every time we build new roads. These findings imply that the ways we traditionally go about trying to mitigate jams are essentially fruitless, and that we’d all be spending a lot less time in traffic if we could just be a little more rational."
Mann also bases the idea on the principle that people like to move around, and will do more of it when given the opportunity. This led him to call road-widening efforts "fruitless," pointing to a traffic study that called such projects “exercises in futility." The study found a 10 percent increase in road capacity resulted in a 10 percent increase in vehicle miles traveled in multiple cities over recent decades.
As for the nearly $2 billion price tag?
When it comes to estimating a cost for a project like this, the Kentucky Transportation Cabinet has begun taking a data-driven approach with Gov. Matt Bevin's initiation into office.
"The initial estimates to budget for a major roadway improvement are determined by engineers using past data of similar projects of scope and magnitude," Wood said. "We collect data from all recently constructed projects and use averages for estimating purposes."
Naitore Djigbenou, acting executive director of public relations for the cabinet, explained that everything from congestion to crash data to economic development potential go into the cabinet's consideration of proposed road projects. The cabinet offers a first round of initial recommendations using a ranking system that considers these factors, then -- as part of Bevin's new approach -- takes further weighted recommendations on a regional level to reach a final list.
"(Each region gets) to prioritize needs in their regions, and by doing that it really helps certain projects be raised to the top," Djigbenou said.
The transportation cabinet will take regional input on projects' priorities this fall, in order to present their final six-year transportation plan recommendations for legislators' consideration in 2018.
Pat LaFleur reports on transportation and mobility for WCPO. Connect with him on Twitter (@pat_laFleur).