Construction of the Portland-Milwaukie Light Rail line will require about a year of traffic detours and bus line changes on Southeast 17th Avenue starting Friday.

TriMet said northbound traffic on the 17th Avenue will be detoured between Holgate and Powell boulevards. Among other things, crews will demolish the Powell Boulevard overpass and build two new structures -- one for the new Orange MAX line and one for motorists, bikes and pedestrians.

The details of the detour:

Vehicles traveling northbound on 17th

Bike and pedestrian detours near the south end of the Eastbank Esplanade begin June 18.

Southbound travel from Southeast Powell onto 17th isn't expected to be affected by the construction.

Two bus lines will be affected.

For about three weeks beginning June 25, cyclists and pedestrians on Southeast Caruthers Street west of Old Water Avenue

Bicycle commuters and pedestrians will not be able to cross Powell at 17th.

The $1.5 billion Portland-to-Milwaukie Orange Line is scheduled to open in September 2015.