Devices designed to slow traffic along Harvard Road in northwest Lawrence are in the works, but neighborhood residents learned at a Thursday meeting they might be asked to help pay for the improvements.

A group of about 40 people met with David Woosley, city traffic engineering manager, to discuss a proposed plan for “calming” traffic on the busy east-west road.

Woosley described a Harvard Road with “traffic-calming circles” — plastic circular devices that would require vehicles to slow on their approach — at Moundridge Drive, Grove Drive and Goldfield Street. The plan also would add speed cushions along Harvard Road between Grove Drive and Justin Street, Wheat State and Eldridge streets, and Andover Street and Prescott Drive.

Speed cushions are speed bumps with two grooves cut through so ambulances and fire trucks can pass without hitting a bump. Woosley said the cushions were not as effective as bumps, but they would not damage emergency vehicles or their passengers.

“What you can’t feel underneath your car, you feel on your teeth,” Lawrence City Commissioner Sue Hack said of a speed cushion she experienced in another city. “You slow down or you pay for it.”

The plan is based on a survey sent in November to neighborhood residents. Woosley said the city would continue to accept comments about the plan through July.

Neighbors voiced several concerns, questioning the effectiveness of the devices. Woosley said that while Lawrence had never strung traffic control devices down a single street, data from other cities showed it slowed traffic.

Woosley said each device would cost about $2,000 to install and would be paid for by taxes from the city at-large, a benefit district for the area or a combination of the two. Neighbors were upset at the possibility of paying for the work, claiming city design caused the traffic problem.

“Why should the people who happened to buy a house there have to pay for a mistake the city of Lawrence planned?” asked Dale Berg, who lives along Harvard Road.

Attendees also expressed frustration about the amount of time it was taking to slow traffic on the street. They began petitioning the city more than three years ago for traffic control. The city installed temporary devices, but they were removed late last winter.