Four additional miles of carpool lanes were opened on Interstate 5 on Wednesday, and they will help cut commuting times by half, according to Caltrans.
Last year, Caltrans opened nine miles of High-Occupancy Vehicle (HOV) lanes on I-5 from Solana Beach to Carlsbad. The added miles will take the carpool lanes through Carlsbad. In all, North County coastal communities will have a total of 13 miles of carpool lanes.
The HOV lanes are a joint project between Caltrans and the San Diego Association of Governments (SANDAG).
“That will reduce the number of cars on the freeway while reducing idling and congestion,” said Lesa Heebner, mayor of Solana Beach and the second vice chair of SANDAG.
Heebner said she's already seen a noticeable improvement in traffic.
"The traffic is riding a lot smoother on the freeways and and ... people are taking advantage of traveling together with other passengers to work or to health care,” she said. "So people are using them. No question about it."
But adding more lanes to freeways is not always the answer. Studies have shown that adding more lanes does not reduce traffic congestion. In fact, it increases it in what's known as induced demand.
Essentially, more lanes induce people to travel more, which means more cars on the roads adding to congestion.
But Allan Kosup, the North County corridor director for Caltrans, said that only applies to general-purpose lanes.
“The carpool lanes are really focused at building an incentive for people to use high-occupant vehicles,” he said.
Kosup said HOV lanes have been shown to reduce commuting times. Caltrans refer to these as managed lanes.
"(Where) we kind of control who's using the lanes and, in doing so, sort of prioritize moving people as opposed to moving vehicles," he said. "So, the idea is to move more people in the lanes."
And the benefit of managed lanes extends to the general-purpose lanes, though to a lesser extent, Kosup said. He pointed to Interstate 15 Express Lanes from Mira Mesa to Escondido as an example.
"The people using the Express Lanes, the car pools, the BRT — the bus rapid transit — see a significant improvement," Kosup said. "It's faster and more reliable than the general purpose lanes even 20 years later."
The southbound HOV lane opened Wednesday, and the northbound lane is slated to open next week.
