A new study suggests many Americans may be missing out on job opportunities within their skill level because they are located outside the range of public transit. About half of the jobs located in American metropolitan areas are considered "high-skill." About one third of these jobs, which include "finance, business and legal services and public administration," are accessible for typical urban commuters via public transportation within 90 minutes, The Brookings Institute discovered. Yet only about a quarter of low-skill and middle-skill jobs are similarly accessible.

"This reflects the greater 'demand for density' among high-skill sectors, and the larger physical footprint of middle- and low-skill sectors like manufacturing and retail," the Brookings researchers observe. "Although both low-income people and jobs have suburbanized over time, poor suburban residents are already less likely to live in a jobs-rich area than their higher income counterparts, and as a result may have to commute farther to find work. This only serves to underscore the challenges facing these residents as they try to connect with employment opportunities throughout the wider metropolitan region."