Hartford — The executive director of the International Bridge, Tunnel and Turnpike Association told the General Assembly’s Transportation Committee Wednesday that electronic tolls would create “a substantial, viable and ongoing revenue source” for the state.

The comments by Patrick Jones came as the committee held a public hearing on a bill that would establish tolls along major highways at the state’s borders, including Stonington.

The state is considering tolls as it tries to find money to upgrade the state’s aging roads and bridges and make other transportation upgrades. Gov. Dannel P. Malloy has made improving transportation one of his top priorities.

Jones told the committee it is not realistic to continue to rely on the state gas tax as a sustainable revenue source because of the increase in the fuel efficiency of vehicles, as well as the growing popularity of electric and hybrid vehicles.

Committee Co-Chairman State Rep. Antonio Guererra, D-Rocky Hill, said he would love an alternative to tolls if there is one out there.

“But I haven’t seen it and we keep kicking the can down the road,” he said, stressing that making improvements is an issue of public safety. “I’m tired that people traveling through our state don’t pay. They ruin our roads and everyone in this room foots the bill. I can’t understand why people don’t understand this.”

But some legislators and residents from western, southwestern and north central Connecticut expressed concerns that drivers would clog local roads and pose additional burden on local police as they try to avoid the tolls. Others said the tolls would stop customers from frequenting Connecticut businesses.

“People are scared to death what would happen,” said Sen. Scott Frantz, R-Greenwich. He said there would be “absolute mayhem” in his town as drivers back up on exits off Interstate 95 trying to avoid the tolls.

Stephen Bull, the chairman of the Greater Danbury Chamber of Commerce, said the tolls would hurt businesses such as the Danbury Fair Mall, which draws half its customers from neighboring New York. He added the state would need a sizeable bureaucracy to collect the tolls.

Sen. John Kissel, R-Enfield, said the tolls would create a parking lot along the three roads in his town that parallel Interstate 91.

Sen. Michael McLachlan, R-Danbury, said a study shows that tolls would force an additional 13,800 drivers onto the streets of Danbury, a pattern he said was sure to happen in Greenwich and Stonington.

No southeastern Connecticut legislators spoke at the hearing. Sen. Andrew Maynard, D-Stonington, who is the committee’s co-chairman, did not attend the hearing.

No estimates are yet available about the cost of implementing tolls or how much revenue they would raise.

Jones said technology would allow the state to collect tolls without booths or plazas. Drivers at highway speed would pass under gantries that would read E-Z Pass-type transponders. Cameras would take photos of the license plates of vehicles without transponders and send the owners a bill.

Jones said this type of system, which is used in places such as Denver, Miami and Austin, Texas, ensures that traffic proceeds smoothly through the tolling locations.

He added that discount pricing could be set up for those in border communities who frequently cross state lines.

The secretary of the Office of Policy and Management, Benjamin Barnes, told the committee that border tolls are “clearly a viable option” among a combination of other revenue sources that would be needed to generate the money needed to fund the improvements. He and legislators pointed out tolls alone could not generate all the money that is needed.

“Tolls are not a panacea or the silver bullet that will solve all our problems with transportation funding,” he said.

He cautioned that tolls set too high would have negative effects on local roads and discourage business in the state.

Barnes said border tolls may not be permitted under current federal law but that could change. He also stressed he is “absolutely opposed” to toll booths and that any tolling would have to be done electronically.

Rep. Tom Odea, R-New Canaan, told Barnes that when the state closed its tolls after a 1983 crash at a Stratford toll plaza killed seven people, it transferred the cost of the transportation system from out-of-state residents paying tolls to Connecticut residents paying the highest-in-the-nation gas tax.

He said lowering the gas tax so it is the lowest in New England could boost revenue because out-of-state residents would come here to buy gas while Connecticut residents now going over the border to buy gas out of state would stay home to buy gas.

Barnes said he did not think the additional gas purchases would offset the loss in revenue from lowering the tax.

In a related issue, Barnes urged the committee to support two proposed bills that would ensure all transportation revenue be spent on transportation improvements, creating a so-called “lock box.”

He said approval of the law would protect the funding until the state can adopt a constitutional amendment to protect the funding in 2016. He said residents’ willingness to pay for road and transportation improvements is related to being assured that the revenue is being spent on transportation upgrades — and not for other purposes — which is what has happened in the past.

Guererra said a lock box would send a clear message that the state is serious about making transportation improvements. Other committee members enthusiastically supported the plan.

j.wojtas@theday.com

Twitter: @joewojtas