The Valley Turnpike: A Macadam Road to Market, and Today's I-81

The Valley Turnpike. MOLLUS, Massachusetts Commandery.

A farmer's crop was worth nothing unless it could reach market — Alexandria, Baltimore, Philadelphia or farther. The Valley's main route, the Great Wagon Road, had improved only slowly, and travelers complained that it was rough and at times dangerous. A petition of 1838 seeking state support for a new road put the case plainly: "The valley seems to be designed as the great thoroughfare between the west and the southwest to northern cities."

Relief had already begun. In 1834 the Virginia General Assembly authorized the Valley Turnpike Company to build a 68-mile macadamized road from Winchester to Harrisonburg; a later extension to Staunton opened up the whole Valley. Businesses, farmers and travelers came to depend on the Valley Pike and the markets it reached, and it became the Valley's lifeblood.

How a macadam road was built

Macadam construction was pioneered by the Scottish engineer John McAdam around 1820. Stone went down in three layers on a sloped roadbed with ditches at the sides for drainage:

A heavy roller pressed the layers until the stones locked together. The result stood up to weather but needed constant upkeep.

The Valley Turnpike was 22 feet wide and at least 12 inches deep. Limestone, the most readily available material, was used almost throughout. Surveyors and engineers also planned its bridges and culverts. Where the old Wagon Road had crossed streams at the easiest ford, the Pike put its bridges on high ground, out of reach of floods.

Building and maintaining the Pike was hard, mostly hand labor. Here a worker breaks limestone into "road metal" of the right size with a round-headed hammer as a farmer hauling lumber approaches. Library of Congress.

The road today: Interstate 81

The Valley's modern thoroughfare, I-81, is a major trucking route carrying an average of 55,000 vehicles a day. It too rests on three layers of strong, compact material:

• Top: concrete, 11 inches
• Middle: natural aggregates — sand, gravel and crushed stone — 21 inches
• Bottom: compacted soil

Sources

Rewritten from the National Park Service article "Vital Route" (Cedar Creek & Belle Grove National Historical Park; public domain), part of the series From Backcountry to Breadbasket to Battlefield and Beyond, in hubnx's own words.