A survey of people walking, running and cycling on the American Tobacco Trail near Southpoint mall suggests that its Interstate 40 bridge has boosted local health and the economy.
Results from May and June 2013 and the same time a year later showed:
That’s according to “Behavioral Effects of Completing a Critical Link in the American Tobacco Trail,” a study released last week by the Institute for Transportation Research and Education (ITRE) at N.C. State University.
The study was intended “to see the impacts on transportation, health and economic behavior in that area,” said Sarah McCue with the state Department of Transportation, which sponsored the study.
“We were very interested in promoting the bicycle and pedestrian use over that bridge,” McCue said. With the bridge, the American Tobacco Trail’s long-separate north and south sections became a continuous 22-mile greenway from downtown Durham to Apex.
ITRE staff, N.C. State students and volunteer researchers collected 2013 data at two trail checkpoints, one north and one south of the bridge site, two miles apart. In 2014 they added a checkpoint near the bridge. At each checkpoint they kept counts of passersby, and asked them to fill out a 19-question survey.
Data collecting went on from 7 a.m. to 8 p.m. on two weekdays and two weekend days each year. The researchers then used mathematical formulas to analyze the information and see what it had to say.
“Our thought was, back in 2012 and 2013 ... wouldn’t it be great if we could get before data and then do an after study,” said Thomas Cook, a program manger with ITRE.
“It’s very seldom a before-and-after study (such as this) has been done,” Cook said. “Usually somebody says, ‘It would have been nice to have done that.’”
For example, the typical trail user was male, 26 to 54 years old, had an advanced degree and an annual household income between $60,000 and $119,999. That profile was the same before and after the bridge opened, and in both years the main reasons people gave for being out on the trail were recreation and exercise.
More than 90 percent of trail outings were round trips – out and back to the starting point. However, there was a 2 percent increase in travel from one point to another, using the trail to get somewhere rather than just for the pleasure of it; and a 4 percent increase in users who got to the trail on foot or bicycle rather than driving there.
“One of the more interesting findings was ... folks that lived to the north of I-40 tended to extend their trip over the bridge and use the trail for a longer distance,” Cook said.
Overall, after cyclists and pedestrians could cross the highway, there was a 27 percent increase in per-trip distance (7.2 miles to 9.3 miles) and a 17 percent increase in active per-week use of the trail (138 minutes to 162 minutes).
That surprised Dale McKeel, bicycle-pedestrian coordinator with the city of Durham. “I guess new horizons to explore led people to increase the amount of time they were on the trail,” McKeel said.
With the increase, according to the report, trail users who took the survey were meeting recommended physical activity guidelines – and burning an estimated 175 million more calories than before the bridge opened.
“We really wanted to get as well a rounded picture as possible of the variety of changes that might have taken place,” Cook said, and the surveys asked about “spending patterns” – both related to the trips they were making at the time and, over the preceding year, “in terms of purchasing running, jogging, bicycling equipment, that sort of stuff.
“We had more people using the trail,” he said. “That resulted in an increase in expenditures.”
Cook’s “ballpark” estimate of the study’s cost was $100,000, paid by the state DOT and the Helen and William Mazer and Blue Cross Blue Shield Foundation.
“I hope that it will be a positive catalyst for ... construction of additional (bicycle-pedestrian) trails,” he said.
The study report does acknowledge that its data “cannot show a true causal relationship between pre- and post-bridge changes in behaviors.”
It adds, though, “It is difficult to attribute the majority of activity increases ... to any event other than the completion of the bridge.”