A reverse commute is a round trip, regularly taken, from a metropolitan area to a suburban one in the morning, and returning in the evening. It is almost universally applied to the trip to work in the suburbs from home in the city. This is on opposition to the regular commute, where a person lives in the suburbs and travels to work in the city.
The reverse commuter is travelling in the opposite direction to the regular daily population flow, so encounters fewer of the road traffic congestion problems faced by regular commuters. Train and bus routes may be more sparse than for those heading into town, but the vehicles have to get back somehow for their next journey in most cases. However, track capacity on some train routes like the Long Island Rail Road Ronkonkoma Branch and the New Jersey Transit Gladstone Branch significantly reduces or even eliminates reverse commute options. Hence, transit usage is lower among reverse-commuters than regular commuters. In some cases, reverse commuting has become quite popular. For example, New York's Metropolitan Transit Authority (MTA) runs peak hour Metro-North Railroad New Haven Line trains from New York City to Stamford, CT and surrounding suburbs to accommodate its many reverse commuters. Low unemployment rates in the suburbs may help to fuel the increase over the past years in reverse commuter ridership.[1] [2], [3]
But the very reasons commuting makes sense (such as higher employment in the city and lower housing prices in the suburbs) operate against the reverse commuter, so people doing so are not common, compared to those going the other way. It is growing, however.
One example would be the reverse commute from San Francisco to Marin County. Companies generally advertise reverse commutes as an appealing benefit to working for the company.
References
http://www.nytimes.com/2008/02/24/nyregion/nyregionspecial2/24Rreverse.html?pagewanted=all, http://www.nytimes.com/2007/08/12/realestate/12wczo.html, http://www.mta.info/mnr/html/planning/schedules/