This paper presents a new approach to the measurement of the effects of spatial mismatch that takes advantage of matched employer-employee administrative data integrated with a person-specific job accessibility measure, as well as demographic and neighborhood characteristics. The basic hypothesis is that if spatial mismatch is present, then improved accessibility to appropriate jobs should shorten the duration of unemployment. We focus on lower-income workers with strong labor force attachment searching for employment after being subject to a mass layoff – thereby focusing on a group of job searchers that are plausibly searching for exogenous reasons. We construct person-specific measures of job accessibility based upon an empirical model of transport modal choice and network travel-time data, giving variation both across neighborhoods in nine metropolitan areas, as well as across neighbors. Our results support the spatial mismatch hypothesis. We find that better job accessibility significantly decreases the duration of joblessness among lower-paid displaced workers. Blacks, females, and older workers are more sensitive to job accessibility than other subpopulations.