Construction has resumed on Route 22 in Westmoreland and Indiana counties as the Pennsylvania Department of Transportation inches closer to completing more than a decade of improvements to a highway once notorious for deadly crashes.

When all of the dust has settled sometime in 2011, all 24.8 miles of Route 22 through Westmoreland County will have been rebuilt to carry four lanes of traffic.

Work to widen the highway to four lanes for the entire 18-mile length of Indiana County is scheduled for completion next year.

In Westmoreland County, three separate but closely linked projects are under way in a 9-mile stretch from just east of Route 981 in New Alexandria to the Indiana County line.

Traffic in most of that stretch has been reduced to one lane in each direction, with reduced speed limits of 35 and 40 mph and some delays expected during peak travel times.

Heading east, the first 4.2-mile section stretches from a quarter-mile east of Route 981 to the Route 982 intersection. The $35 million project will expand the highway to four 12-foot-wide concrete lanes; add a traffic signal at Rushwood Road; and improve the median, shoulders, guide rail and drainage. Completion is expected in August, said Valerie Petersen, spokeswoman for PennDOT District 12.

A 1.9-mile section from Route 982 to Auction Barn Road also is being widened to four concrete lanes under a $19.6 million contract that is to be completed in 2010.

The final section is 2.5 miles from Auction Barn Road to the county line. In addition to providing four traffic lanes, the $34 million project includes a new bridge over Stoney Run and a traffic signal at Jonnet Road. The tentative completion date is July 2011.

In Indiana County, work is continuing on a $46 million widening and reconstruction of a 4.8-mile section of Route 22 in East Wheatfield and West Wheatfield townships, with that work scheduled for completion in June 2010, said PennDOT District 10 spokesman Harold Swan.

In all, more than $400 million will have been spent on construction done in nine separate phases on the Westmoreland County stretch of the road, going back to 1999, and three phases in Indiana County, going back to 2002.

Before the Pennsylvania Turnpike was opened in 1940, Route 22, also known as the William Penn Highway, was the principal route from Pittsburgh to Harrisburg and New York.

Before the improvements started, much of the highway was one lane in each direction, with a center lane used for passing by traffic in both directions, a design that contributed to scores of high-speed crashes.