Driverless cars may still be a few years away, but Tennessee highway officials say they're already starting to invest in intelligent technologies to help with congestion woes.
At a budget hearing, the head of the Department of Transportation claimed that the state is among the leaders in studying how to use data to move traffic more efficiently.
Tennessee has more money for roads, thanks to an increase in the gas tax that went into effect this summer. But along the state's busiest corridors, Transportation Commissioner John Schroer says there's another problem: no land to expand.
"We're going to be looking at how we do things, within our department, different from just adding new lanes," he says. "And in urban areas, we don't have the real estate to add new lanes."
Those new ideas include harvesting more information from vehicles. Schroer says many cars and trucks on the road now already collect data that could make highways more efficient.
The California Department of Transportation is already piloting one such program. Its I-80 Smart Corridor in the San Francisco Bay area uses traffic data to warn drivers of upcoming congestion and route them around accidents using secondary roads. Greenlights on those roads are simultaneously extended to keep traffic moving, and message boards tell them when they've passed the accident.
The system also lowers the speed limit during high traffic and controls traffic lights on ramps to time when cars enter the highway. Engineers hope to slash the number of accidents along a stretch of road where they've been twice as high as comparable roads.
Squeezing more out of existing roads is going to be increasingly important, Schroer says. The surge in funding from the gas tax increase will fade with inflation and the expected switch from gasoline to electric vehicles.
State officials also say they're losing hope the federal government will step up spending on roads and bridges. They note that, even if it were to get through Congress, the $1 trillion infrastructure program that President Donald Trump touted during last year's campaign actually includes only $200 billion in government funds. The rest is supposed to be supplied by the private sector through partnerships such as toll roads, which are unlikely to be built in Tennessee.