FOXBORO - Police Chief Edward O'Leary is seeking data to make a case to convince the state to install a traffic signal at Walnut and Commercial streets.

O'Leary said patients and other drivers coming from the Caritas Foxboro medical center at 70 Walnut St. may find it impossible to safely take a left turn across Commercial Street (Route 140).

Northbound vehicles on Route 140 come around a gradual curve in the state highway at expressway speeds, whizzing past the intersection just a few seconds after becoming visible from Walnut Street.

Patrons and volunteers at the Foxboro Discretionary Fund farm stand face the same risks at the intersection.

Residents are trying to keep the pressure on officials to make improvements both at the intersections of Route 140 and Walnut Street, near the farm stand, and at Central Street, near Papa Gino's. Having witnessed several near-accidents, Alice Berberick of 12 Spring St. says she never tries to make the left turn onto Route 140 from Central Street or from Walnut Street near the farm stand.

"I feel that we have just been lucky so far not to have more accidents at these intersections," Berberick wrote to selectmen in a July 29 letter asking for installation of traffic lights at both intersections.

O'Leary said he regards the Walnut Street intersection as the more dangerous of the two, because of the faster speeds of traffic on Route 140 there, and because some patients leaving the health center may have slower reflexes.

The chief said the state Highway Department is reviewing its records for traffic data at Walnut and Route 140, while he is asking the Metropolitan Area Planning Council to do a traffic study.

Town manager Andrew Gala said improvements to the state highway should be paid for by the state.