The mad dash to catch a rush-hour commuter train is about to get more complicated for tens of thousands of riders, as the MBTA prepares to install fare gates similar to those in the subways at its three busiest stations in order to improve fare collections.

They’re probably coming to North Station first, sometime in the first half of 2020, before rolling into the Back Bay and South Station later in the year, according to rail operator Keolis Commuter Services, which will install the gates for the MBTA.

Where exactly, though, is not completely settled for all three stations. At North Station, for example, Keolis has all but finalized plans to put gates along the perimeter of the main waiting area, where passengers congregate to learn at which platforms their trains will arrive.