Use of Houston’s high-occupancy toll lanes has reached a tipping point that risks slowing carpoolers and transit riders, prompting Metro officials to make a last stab at enforcement before a more drastic — and some think inevitable — crackdown on HOV rules.

“The first people we should inconvenience are those cheating the system,” said Sanjay Ramabhadran, a Metropolitan Transit Authority board member.

As a result, drivers will see more Metro police along the HOT lanes on most Houston-area freeways, where transit officials oversee the lanes and allow toll-paying solo drivers for most of the day.

It is the peak morning and evening commuting periods when solo drivers are not allowed in the lanes that pose a problem. As use of the lanes increases, traffic slows, with the maximum use of a freeway lane at about 2,200 vehicles per hour. More than that, and speeds decrease below the goal of a 45 mph average.

For the most part, the proposed changes and crackdown will affect only the peak hours of the morning and evening commutes, from 6:30 to 8 a.m. and 4:30 to 6 p.m.

Metro operates the lanes on Interstate 45, Interstate 69 and U.S. 290. The managed lanes along Interstate 10 in Katy are controlled by the Harris County Toll Road Authority.

Based on recent months, both I-45 north of downtown during the morning and I-69 south of downtown in the morning and evening are teetering just above the 45 mph threshold.

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As a result, staff suggested raising carpool occupancy — how many people are in a vehicle to be eligible — from two people to three during peak times along all of I-45 and I-69 south of downtown. The lane along U.S. 290 already is restricted to three-person carpools in the morning.

Rather than increase carpool requirements, board members said last week they wanted more police presence in hopes they can delay a change in the carpool rules and move two-rider vehicles back into the general use lanes. Officials called it a pilot program of heavier enforcement, meant to last through December.

“It won’t take many days for them to see an officer out there all the time to get the idea,” Metro board member Jim Robinson said of solo drivers who ignore the rules.

Robinson said he often sees solo drivers in the HOT lanes, though he and Metro officials said they could not estimate the solo use and how it will affect peak HOT lane times.

“That’s what this pilot is for,” Robinson said. “We are going to have to pull some of those people off.”

He added that Metro needs to make the rules more clear, perhaps with new signs, so drivers know when the lanes are for carpool users only.

Drivers, meanwhile, say the lanes face a lot of issues and policing is just one of them.

“What slows them down is the wrecks and stalls,” I-69 HOT lane user Brian Joseph said, “and the construction.”

Built in 1984 specifically for park and ride buses, the lanes were opened to carpools a year later and to solo drivers in 2012, when capacity allowed it.

Enforcement, however, is not easy on the HOT lanes — typically built as single, reversible lanes in the center of the freeway with concrete walls on each side. The crowded freeway right of way makes it difficult, and in some cases dangerous, to deploy a police officer to write tickets.

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Policing also messes with the flow of the lanes, said Tim Kelly, Metro’s executive vice president for customer service and safety.

“When we enforce, we slow down traffic considerably,” Kelly said. “We get more complaints when we do enforcement than when we don’t.”

Nevertheless, board members agreed they have to show they are enforcing the rules before changing them.

“We should be making this as convenient as possible for people who are carpooling,” Ramabhadran said.

Using police enforcement to free up capacity is not sustainable for the long haul, Metro CEO Tom Lambert said.

Instead, he and board members say, Metro will prioritize changes based on what the lanes are meant to do. Changes are likeliest first for when solo drivers and carpools carrying two people can use the lanes. Van pools and buses increasingly will receive priority, Lambert said.

“That carpool is two people or three people,” he said. “That bus is 45 people.”

dug.begley@chron.com