\nDuring the past four decades, the obesity rate for children ages 6 to 11 has more than
\nquadrupled (from 4.2% to 17%), and it has more than tripled for adolescents ages 12 to 19
\n(from 4.6% to 17.6%).1, 2 Regular physical activity can reduce the risk for obesity and help
\npeople lead longer, healthier lives. Yet studies show that less than half of U.S. children and
\nadolescents meet the recommended guidelines of at least 60 minutes of daily moderateto-
\nvigorous physical activity.3\u20135 The same studies indicate that less than 10 percent of adults
\nin the U.S. get the recommended 30 minutes of moderate-to-vigorous physical activity
\nper day.6\u20138\n<\/p>\n
\nWalking and bicycling for daily transportation are important sources of physical
\nactivity, but they have declined dramatically over the past few decades. Between 1977
\nand 1995,a the number of all walking trips decreased by 32 percent, and there was a similar
\ndecrease in trips made by adults walking to work.9 Adults walk for only 21.2 percent of
\ntrips that are one mile or less, and children walk for only 35.9 percent of trips to school
\nthat distance.10 Reversing the decline in rates of walking and biking for transportation,
\nespecially for short trips, presents a major opportunity for improving health among
\nchildren, adolescents and adults.\n<\/p>\n
\nTransportation investments can either support or impede walking and bicycling in
\nneighborhoods and near schools, depending on how they are implemented. Evidence
\nis accumulating about how infrastructure improvements, programs that aim to manage
\nneighborhood road traffic, and efforts to make streets and sidewalks safer for active travel
\ninfluence travel patterns among both children and adults. This research brief presents
\nan overview of findings demonstrating the potential impact of infrastructure investments
\nand other transportation programs on walking and bicycling for transportation, and on
\nrelated health outcomes. It focuses on public transit, greenways and trails, school-related
\ninfrastructure and programs, pedestrian and bicycle facilities, and efforts to manage
\ncar traffic.<\/p>\n
<\/p>\n
\nKey Research Results\n<\/p>\n
\n* People who used public transportation (i.e. subways, commuter rails, light rails, buses, trolleys,
\netc.) for any reason were less likely to be sedentary or obese than adults who did not use public
\ntransportation.11\u201313 Nationwide, 29 percent of those who use transit were physically active for
\n30 minutes or more each day, solely by walking to and from public transit stops.14 Similarly, transit
\nusers took 30 percent more steps per day and spent 8.3 more minutes walking per day than
\ndid people who relied on cars.15 Conversely, reliance on the automobile for travel was associated
\nwith higher obesity rates at both the county16 and individual level.17\u201320\n<\/p>\n
\n* With few exceptions,21 proximity to public transit stops was linked to higher transit use and higher
\nlevels of physical activity among adults.22\u201326 A study conducted in Salt Lake City, Utah, found
\nthat 18.8 percent more residents used the rail system after a new rail stop opened in their area.27\n<\/p>\n
\n* The physical activity associated with transit use saves money. According to one study of obesityrelated
\nmedical costs, the extra walking related to transit use was estimated at a lifetime savings
\nof $5,500 per person in 2007 dollars.28 When accounting for decreases in quality of life, such as
\ndisabilities
\nrelated to obesity, the estimated savings were even higher.29,30\n<\/p>\n
\n* Most studies of children and adolescents indicate that walking or bicycling to school is related to
\nhigher overall physical activity.32 However, the percentage of school-age children nationwide who
\ncommute to school by walking or bicycling decreased by 68 percent from 1969 to 2001.33, 34\n<\/p>\n
\n* Parents\u2019 perceptions of the transportation route between home and school were among the
\nkey factors determining whether children walk or bike to school.35, 36 Perceived safety from traffic
\nand crime have been associated with higher rates of children walking and bicycling to school.37, 38
\nA survey in Melbourne, Australia, found that children ages 5 to 6 and ages 10 to 12 whose parents
\nbelieved they had to cross several roads to get to play areas were between 40 percent and
\n60 percent less likely than other children to walk or bicycle to school or parks at least three times
\nper week.39\n<\/p>\n
\n* Promotional and educational programs helped increase rates of biking and walking to school.40\u201342
\nParental safety concerns about traffic tend to be a common obstacle to biking and walking to
\nschool,43\u201345 but addressing safety behaviors and concerns through educational programs appears
\nto be a promising strategy. For example, US Walk to School programs have been associated
\nwith higher walking rates.46 Additionally, the WalkSafe program, an educational injury-prevention
\nprogram
\nin Miami-Dade County, Fla., has led to children who are more likely to engage in safe
\npedestrian behaviors (e.g., stopping and looking when crossing the street) or avoid unsafe
\nbehaviors
\n(e.g., mid-street crossing and darting out) than were those who did not participate,
\na change which was sustained over time.47\n<\/p>\n
\n* Efforts promoted by programs such as Safe Routes to School, including building sidewalks, crosswalks
\nand traffic-control devices around schools, have been linked to both increases in the
\npercentage of students who walked to school48\u201352 and reductions in the percentage of students
\nbeing driven to school.53 Up to 39 percent of the land in large U.S. urban areas is within one-half
\nmile of a public school, so physical improvements in neighborhoods surrounding schools provide
\nsafer walking environments not just to students, but also to residents in the surrounding
\nneighborhoods.54\n<\/p>\n
\n* More and better-quality sidewalks are associated with adults having both higher rates of walking
\nand of meeting physical activity recommendations,56\u201361 and with a lower likelihood of being
\noverweight.62\u201364 Similarly, the presence of bicycle lanes and paths is positively related to cycling,65
\nand to more adults meeting physical activity recommendations.66\u201370 Cities that invest in bicycle
\nfacilities exhibit higher levels of bicycle commuting.71\n<\/p>\n
\n* A survey of more than 11,500 participants in 11 countries found that residents of neighborhoods
\nwith sidewalks on most streets were 47 percent more likely to get moderate-to-vigorous physical
\nactivity at least five days per week for at least 30 minutes each day than were residents of
\nneighborhoods
\nwith sidewalks on few or no streets.72 A review of 16 studies found that people
\nwho reported having access to sidewalks were 20 percent more likely to be physically active
\nthan those reporting no access to sidewalks.73\n<\/p>\n
\n* One study of cities across the country estimated that, for every 1 percent increase in the length
\nof on-street bicycle lanes, there was a 0.31 percent increase in bicycle commuters.74 Studies
\nconducted in Minneapolis, Minn., and Portland, Ore., showed that bicyclists were willing to go
\nfarther than they would normally in order to use safe bicycle infrastructure.75\u201377\n<\/p>\n
\n* Two studies found that facilities for bicycle parking, personal showering and locker storage at
\ndestinations were a promising strategy for promoting cycling and walking.78, 79 The monetary
\nvalue of the benefits of having destinations with facilities to support walkers and bicyclists was
\ncalculated at between $0.96 and $1.92 per bicycle trip.b\n<\/p>\n
\n* Building multi-use trails can lead to short- and long-term increases in walking and cycling,
\nespecially
\non urban-area trails and trails that connect population centers with desirable
\ndestinations,
\nsuch as downtowns.81\u201383 Furthermore, trails have been shown to be particularly
\nbeneficial
\nin promoting physical activity among women and people in lower-income areas.84\n<\/p>\n
\n* With few exceptions,85 living near trails or having trails in one\u2019s neighborhood has been associated
\nwith people being 50 percent more likely to meet physical activity guidelines86, 87 and 73 percent to
\n80 percent more likely to bicycle.88 In a nationally representative study, individuals who reported
\nusing trails at least once per week were twice as likely to meet physical activity recommendations
\nas were those who reported using trails rarely or never.89 In a sample of pre-adolescent girls,
\nproximity
\nto trails was related to 4.8 percent more physical activity and a 1.4 percent lower body
\nmass index.90\n<\/p>\n
\n* The financial gain of the health benefits related to trail use outweighed the cost of building and
\noperating the trails.91, 92 For example, in Lincoln, Neb., every $1 invested in trails was estimated to
\nsave $2.94 in direct medical costs from a societal perspective.93\n<\/p>\n
\n* Fast and heavy traffic is commonly cited by youth and adults as a barrier to walking and cycling.94\u201398
\nInfrastructure changes that decrease vehicle speeds, increase the attention of drivers and enhance
\npedestrian safety are known as traffic-calming devices. Devices such as speed bumps and
\nvisibility
\naids can improve pedestrian and bicyclist safety. Other devices, including reductions in the
\nnumber or width of car lanes, sidewalk extensions into traffic lanes at street crossings, and space
\nfor cars to park along the roadway, can help pedestrians but may be detrimental for bicyclists.\n<\/p>\n
\n* Several recent reviews have examined how traffic-calming influences the risk of crashes involving
\npedestrians, and that of automobile crashes resulting in injuries. One found that traffic-calming
\nsubstantially reduced the risk of crashes involving pedestrians,99 while another did not detect
\nreductions
\nin crashes involving pedestrians after such changes.100 The second of these reviews,
\nalong with a third one, suggested that traffic-calming efforts resulted in 11 percent to 15 percent
\nlower rates of automobile crashes with injuries.101, 102 Traffic calming on residential streets may
\nhave a greater effect than doing so on main streets.103\n<\/p>\n
\n* With few exceptions,104 high levels of vehicular traffic have been associated with lower rates of
\nphysical
\nactivity in nearby areas.105, 106 Accordingly, some of the benefits of traffic calming included
\nincreased walking and cycling, and enhanced opportunities for outdoor play among children
\nand adolescents.107\u2013111 In one study, the number of observed pedestrians increased after the
\nintroduction
\nof neighborhood traffic calming, and 20 percent of respondents reported they
\nwalked more in the area as a result of the calming effort.112\n<\/p>\n
\nConclusion\n<\/p>\n
\n* A substantial body of research shows that certain aspects of the transportation
\ninfrastructure\u2014public transit, greenways and trails, sidewalks and safe street
\ncrossings near schools, bicycle paths, traffic\u2013calming devices, and sidewalks that
\nconnect schools and homes to destinations\u2014are associated with more walking
\nand bicycling, greater physical activity and lower obesity rates.\n<\/p>\n
\n* Beyond improving local travel options, transportation infrastructure investments
\nthat support physical activity can result in increased recreational opportunities,
\nimprovements to individuals\u2019 health and decreased health care costs.\n<\/p>\n
\n* In combination with infrastructure investments, programs that raise awareness
\nand complement pedestrian and bicycle facilities are promising options for
\nsupporting physical activity. Specifically, Safe Routes to School programs and
\nthe management of traffic in local neighborhoods and around schools have
\nbeen shown to affect physical activity among children, adolescents and adults.\n<\/p>\n
\n* Fast vehicle traffic is a significant barrier and danger to bicyclists and pedestrians.
\nMeasures to slow down traffic and to help pedestrians negotiate busy streets
\ncan be effective in increasing physical activity and improving safety.\n<\/p>\n
\n* Addressing the decades\u2013long decline in walking and bicycling for transportation
\nrequires changing the physical characteristics of our communities. Federal, state
\nand local policies and funding that support the type of infrastructure investments
\nand programs identified in this brief can help slow and perhaps even reverse
\nthis decline.\n<\/p>\n