People are more likely to go for a walk in areas with four-way intersections and a large number of shops and businesses as possible destinations, a large new study finds.

The study examined pedestrian trips in 10 major U.S. cities to determine to what extent urban design guidelines increase walking.

Only two of four smart growth criteria investigated held up as reasons for walking the presence of four-way intersections and a diverse business environment.

The other two housing density and the length of a city block did not appear to have any impact on the probability of walking, the study found.

"I see our study as a step on the way to evidence-based guidelines for design of the built environment in order to make it more conducive to walking," said Rob Boer, Ph.D., who led the RAND Corp. research team.

The study appears in the April issue of the American Journal of Preventive Medicine.

The researchers used data from a 1995 transportation survey that included interviews of 42,033 households nationwide. Study cities were Boston, Chicago, Dallas, Detroit, Houston, Los Angeles, New York, Philadelphia, San Francisco and Washington.

The guidelines are part of a movement embraced by the U.S. Environmental Protection Agency to develop sustainable communities. The criteria were spelled out in the New Urbanism Smart Scorecard, a tool for city planners and developers to determine whether a project fulfills smart-growth goals.

"The built environment is a powerful influence on walking," said Chaya Gordon, senior research manager at the American Society on Aging. "RAND's study of the association between Smart Scorecard factors and increased walking is a valuable contribution to understand the effect of particular neighborhood design features." Gordon was not involved with the study.

Boer acknowledged that he didn't know why four-way intersections had such a positive impact on walking but suggested "there may be more connectivity" within a neighborhood.

"But the number of businesses makes more sense," he said. "Does it help to have destinations to make people walk more? The answer is yes."