Mass transportation is undergoing large surges in growth in large metropolitan areas as the need to connect urban areas with surrounding transit points increases. Metro stations are usually incredibly crowded with people so efficient smoke & fire protection is crucial.
One of the largest obstacles with protecting a metro station is the fact that they are typically underground. Underground stations have limited egress routes for smoke. For that reason, smoke exhaust systems are used at length. However, with the addition of smoke & fire rated curtains smoke exhaust systems can increase in effectiveness without having to increase in cost and maintenance. Plus, smoke curtains help section off areas of the station to allow for the exit of any patrons.