Season one of three is complete on a $26 million Interstate 5 repair project south of Ashland.
‘It’s a wrap just in time before the snow flies,” said ODOT Consultant Project Manager Chris Hunter of the October 15 deadline.
The southbound interstate slow lanes have been rebuilt with new reinforcing steel and concrete between milepost 11 to 9. Rutted and damaged concrete, as well as exposed reinforcing steel were replaced after three decades of use.
For drivers, that meant several months of single lane traffic for two miles in each direction, separated by barrier, south of Ashland on the climb up to Siskiyou Summit. For southbound traffic climbing the grade, that meant speeds were as fast as the slowest truck. The construction speed limit was 40 mph.
“The concrete installed in the late 1980s has stood the test,” said ODOT Ashland Maintenance Manager Everett Carroll. The original I-5 road surface was asphalt when the Siskiyou Summit section opened in 1966.
On tap for the rest of the project will be “diamond grinding” or leveling the lightly-rutted concrete surface and rehabilitating damaged concrete pavement. In some locations that means repairing or completely replacing concrete panels so there will be some additional crossovers. Guard rail replacement and shoulder/ramp paving are also in store.
Because the project location is in a snow zone – with Siskiyou Summit at 4,310 feet – construction timelines are limited to late spring through fall.
Next year the first of the bridges will undergo a major renovation. The twin bridges at Exit 6 over Old Siskiyou Highway will see their decks completely replaced. Decades of winter maintenance activities, freeze-thaw and chemical deicers have been hard on the bridge’s concrete and steel rebar decks.
Instead of a superficial deck fix, the entire bridge deck – concrete and steel reinforcing bar – will be replaced. Once removed, the contractor will rebuild the entire deck from the horizontal beams up, a process that will take several months to complete.
For interstate drivers, that means both directions of traffic will be moved onto one bridge. With two lanes of traffic running head-to-head, separated by a concrete barrier, precautions are being made for trucks with loads wider than 12 feet.
“A temporary on-ramp will be constructed from old Siskiyou Highway as a way for over-wide southbound trucks to bypass the narrow bridge width,” said Hunter. For example, the southbound lanes on the northbound bridge will be restricted to 15 feet total between concrete barriers. Northbound width will be 22 feet. Those oversized loads will divert onto the Exit 6 southbound ramp and then back on at the temporary ramp. Traffic coming north on Old Siskiyou Highway will need to stop for that traffic.
Local Traffic Impacts
During bridge demolition, traffic under the bridge will be closed temporarily for safety. That will result in some out-of-direction travel for residents living on both sides of Interstate 5 near the summit. Residents east of I-5 may need to use Old Siskiyou Highway to Oregon 66 for a time to travel north. Those on the west side of the interstate may need to drive south to Hilt, California and back north toward Ashland.
Hunter said the contractor will work hard to get the area under the bridge passable as soon as possible for drivers and Pacific Crest Trail through-hikers who divert from the trail for some rest and relaxation at Ashland.
“It’s been about 33 years since we’ve had such a large impact to travelers on both the interstate and the local highway,” said Hunter. “The bridge work will mean more impacts but we’ll do our best to work with the contractor, communicate the schedule and keep everyone connected.”