Motorists heading south on the Maine Turnpike on Labor Day ran into a 19-mile-long traffic jam as they approached the New Hampshire border.

The culprit wasn’t the York toll plaza. Traffic never breached the plaza’s capacity of 4,000 cars per hour, turnpike officials say. In fact, as soon as drivers paid the $2 toll, they hit a traffic jam south of the plaza.

The real bottleneck is the Piscataqua River Bridge at the New Hampshire border, said Peter Mills, the Maine Turnpike Authority’s interim executive director.

Every Labor Day and on Sundays in August, he said, the bridge causes traffic to back up from the border north through the York toll plaza — seven miles from the bridge — and sometimes all the way to Exit 19 in Wells.

“The cause of congestion in getting out of Maine right now is not the tollbooth,” Mills said. “It’s the high-level bridge.”

The Labor Day traffic jam prompted Mills to ask New Hampshire Turnpike officials Thursday to begin discussing how the two states can work together to address the problem.

Christopher Waszczuk, administrator of the New Hampshire Bureau of Turnpikes, said Friday that he hopes to meet with Mills within the next few months. He said New Hampshire officials are concerned about northbound traffic congestion that occurs from 3 to 5 p.m. on Fridays in the summer, when commuters and tourists travel at the same time.

Waszczuk concurs with Mills that the Piscataqua River Bridge slows traffic. He said the curve in Interstate 95 just south of the bridge, and the interchanges and ramps in Portsmouth, N.H., also slow down traffic.

The problem with the bridge isn’t its capacity. It has three lanes in each direction, just like the stretch of I-95 on either side of the bridge.

The problem appears to be human nature, Mills said.

The bridge’s centerpiece is a 1,344-foot-long steel arch span, which was the widest such span when it was built in 1972. The bridge gives ocean vessels 135 feet of clearance — and creates traffic problems.

Motorists going in either direction must drive uphill to pass over the bridge, and the grade causes them to go a bit slower.

The bridge also offers a spectacular view of the Piscataqua River and Portsmouth’s waterfront. The result: Motorists ease off the gas as they look to the side.

Marshall Jarvis, a spokesman for Think Again, the citizens group that has opposed the Maine Turnpike Authority’s years-long effort to build a new toll plaza in York, agrees with Mills’ assessment.

“It’s an incredible view” from the bridge, he said. “It just causes people to slow down.”

Jarvis and others have long argued that a new, expanded toll plaza in York would not relieve summer traffic jams because the real culprit is the Piscataqua River Bridge.

Jarvis, who lives in York, observed the Labor Day traffic at the toll plaza from an overpass. He said southbound drivers who passed through it immediately ran into more traffic.

“I have seen it happen over and over,” he said. “It’s very clear to me that the backup doesn’t start at the tolls. It starts well into New Hampshire.”

The Piscataqua River Bridge is owned by both Maine and New Hampshire. In an email to officials in New Hampshire, Mills offered ideas from his staff and consultants for reducing congestion on the bridge, including:

Eliminating a breakdown lane and re-striping the bridge to create four travel lanes in each direction.

Using movable barriers to change the direction of traffic in one lane, creating four northbound lanes on Fridays and Saturdays in August and four southbound lanes on Sundays.

Erecting a curtain barrier on the upwind, upstream side of the bridge to reduce wind buffeting and discourage drivers from rubbernecking.

In another 15 years or so, the bridge deck must be rebuilt, Mills wrote. “That may be a good time to make alterations, but we need to develop a plan now and do other things in the interim.”

While the Maine Department of Transportation is responsible for the bridge, the department is focused on other pressing needs, Mills said.

He said the Maine Turnpike Authority is willing to commit money to improve the bridge because it is the gateway to the turnpike. He said that reducing traffic congestion is critical to Maine’s economy, particularly its tourism industry.

“This is how we are all linked,” he said. “If the tourists can’t get through New Hampshire, they are not going to be happy with us.”

Mills, who was appointed interim executive director after the resignation of longtime director Paul Violette in March, will meet with York selectmen and state legislators from the area today to give them an update on the toll plaza project.

Before Mills’ appointment, the turnpike authority was planning to move the York toll plaza despite opposition from the towns of York, Ogunquit and Wells.

For years, turnpike officials have wanted to build a toll plaza with a mix of conventional tollbooths and high-speed open-road tolling, similar to what was built last year at the Hampton toll plaza in New Hampshire.

New Hampshire officials say the improvements have eliminated significant summertime traffic jams at the tolls.

Maine’s toll plaza expansion is on hold. Mills said the turnpike authority recently hired consultants Wilbur Smith Associates, a national firm based in South Carolina, to re-examine the options.

Mills said the firm will look at the feasibility of eliminating tollbooths completely and replacing them with a system in which people either pay with their E-ZPass accounts or are mailed bills.

That system, supported by many York residents, would require workers to view photo images of license plates and mail out bills to the owners of the vehicles.

The system has been used in other states, including Texas and Florida, but Mills said he is skeptical that it could be successful in Maine because so many motorists come from other states and leave Maine after they visit.

MaineToday Media State House Writer Tom Bell can be contacted at 791-6369 or at:

tbell@mainetoday.com