Over the next 10 weeks, transportation planners will stop and ask a number of drivers where they've been, where they're going and why.

One-day checkpoints will be set up in the outbound direction at 26 different highway locations, on the perimeter of a bloc of 10 counties that make up the Southwestern Pennsylvania Commission

In Washington County, for example, westbound traffic will be polled on Route 22 one day and on Interstate 70 on another day, both near the Ohio line.

A national traffic consulting firm, Wilbur Smith Associates, will compile the results and build a computerized "traffic model," part of a year-long, $600,000 study being conducted jointly by the SPC, which sets highway funding priorities for the region, and the Pennsylvania Department of Transportation.

SPC Executive Director Jim Hassinger said that the addition of Indiana, Fayette, Lawrence and Greene counties into the agency in recent years necessitates an updated look at highway travel patterns for commercial vehicles as well as passenger vehicles.

"It enables us to get a fresh look at the origins and destinations of people moving in and out of the region," Hassinger said. "Were they here for business or pleasure? It enables us to make better-informed decisions when we plan road and maintenance improvements."

The program is officially called "Travel View," which includes Pit tsburgh and Allegheny, Butler, Armstrong, Beaver, Westmoreland and Washington counties in addition to four newer member-counties.

The consultant will utilize PennDOT employees and state police to establish safe traffic control methods during the survey periods.

The surveys will be conducted by direct interviews and-or by distributing postage-paid, mail-back questionnaires.

Officials said most drivers who will be stopped should be delayed about two minutes, with no vehicle experiencing more than a five-minute delay. Interviews will be conducted from 11 a.m. to 7 p.m. on a Tuesday, Wednesday or Thursday.

Some of the other 26 locations include Routes 40 and 30 in the Laurel Highlands; Route 8 north of Butler; I-79 in Greene County at the West Virginia line; I-79 in Lawrence County at the Mercer County line; Route 22 in Indiana County at the Cambria County line; and Route 51 in Beaver County.

The Pennsylvania Turnpike is not included in the survey.