Franco Tentori and other volunteers escorted children to school in Lecco, Italy, along one of 17 ‘‘piedibus’’ walking routes.

By ELISABETH ROSENTHAL


LECCO, Italy - Each morning, about 450 students travel along 17 school bus routes to 10 elementary schools in this lakeside city at the southern tip of Lake Como. There are zero school buses.

In 2003, to confront the triple threats of childhood obesity, local traffic jams and a rise in global greenhouse gases abetted by car emissions, an environmental group here proposed a retroradical concept: children should walk to school.

They set up a piedibus (literally foot-bus in Italian) - a bus route with a driver but no vehicle. Each morning a mix of paid staff members and parental volunteers in yellow vests lead lines of walking students along Lecco’s twisting streets to the schools’ gates, stopping here and there as their flock expands.

At the Carducci School, 100 children, or more than half of the students, now take walking buses. Many of them were previously driven in cars. Giulio Greppi, a 9-year-old with shaggy blond hair, said he had been driven about half a kilometer each way until he started taking the piedibus.“I get to see my friends and we feel special because we know it’s good for the environment,”he said.

Although the routes are each short, the town’s piedibuses have so far eliminated more than 160,000 kilometers of car travel and, in principle, prevented thousands of tons of greenhouse gases from entering the air, Dario Pesenti, the town’s environment auditor, estimates.

The number of children who are driven to school over all is rising in the United States and Europe, experts on both continents say, making up a sizable part of transportation’s contribution to greenhouse-gas emissions. The“school run”made up 18 percent of car trips by urban residents of Britain last year, a national survey showed.

In 1969, 40 percent of students in the United States walked to school; in 2001, the most recent year data was collected, 13 percent did, according to the federal government’s National Household Travel Survey.

Lecco’s walking bus was the first in Italy, but hundreds have cropped up elsewhere in Europe and, more recently, in North America to cut down on driving. Towns in France, Britain and elsewhere in Italy have created such routes, although few are as extensive and longlasting as Lecco’s.

Although carbon dioxide emissions from industry are declining on both continents, those from transportation account for almost one-third of all greenhouse-gas emissions in the United States and 22 percent in European Union countries. Across the globe, but especially in Europe, where European Union countries have pledged to reduce greenhouse gas production by 2012 under the United Nations’ Kyoto protocol, there is pressure to reduce car emissions.

Last year the European Environmental Agency warned that car trips to school were growing phenomena with serious implications for greenhouse gases.

In the United States and in Europe,“multiple threads are warping traditional school travel and making it harder for kids to walk,”said Elizabeth Wilson, a transportation researcher at the Humphrey Institute of Public Affairs at the University of Minnesota. Among those factors are a rise in car ownership; cuts in school-bus service as a result of school-budget cutbacks ; and the decline of neighborhood schools and the rise of school choice, meaning that students often live farther from where they learn.

In Britain, about half the local school systems now have some sort of incentives to encourage walking, said Roger L. Mackett, a professor at the Center for Transport Studies at University College in London.

“It’s quite a lot of effort to keep it going,”he said.“It’s always easier to put children in the back of the car. Once you’ve got your two or three cars, it takes effort not to use them.”