Incoming Celtics player Kelly Olynyk will help the T inaugurate the first electronic signboard to let you know the next trolley is approaching/arriving, in a ceremony tomorrow at 2 p.m. at Kenmore station.

For the first time on the Green Line, electronic message boards will provide "Next Train" information.

The T says it will explain exactly what that means at the ceremony.

Olynyk, who went to Gonzaga, will then ride the Green Line to North Station with state Transportation Secretary Richard Davey, who went to Gonzaga law school.