One lane of Interstate 84 in each direction will be closed until fall as construction continues for a rebuilt eastbound bridge over McCord Creek.  Both directions of traffic are sharing the westbound bridge over the creek for about four months while crews work to remove and rebuild the eastbound bridge.  In the summer and fall, the eastbound and westbound bridges will be open but one lane in each direction will remain closed.  Traffic delays are expected, and the Oregon Department of Transportation is asking motorists to use zipper merging when approaching closed lanes.  Zipper merging is when drivers remain in their current lane until the lane ends so vehicles can take turns merging.  The NE Frontage Roand on-ramp to eastbound I-84 at the Elowah Falls Trailhead parking lot is also closed.  Travelers accessing eastbound I-84 from NE Frontage Road must detour to the on-ramps at Ainsworth State Park exit 35.