Improvements urged for Hwy. 1 and Foothill Boulevard in San Luis Obispo to mitigate traffic

Major improvements are needed at the intersection of Foothill Boulevard and Highway 1 in San Luis Obispo within the next five years to prevent extreme traffic delays, according to a study presented to the City Council on Tuesday.

Dubbed the “Major Investment Study,” the 103-page document is intended to guide city leaders in managing traffic along San Luis Obispo’s portion of the highway northwest of downtown, which is also called Santa Rosa Street.

The study identifies existing traffic troubles and improvements that could be be made to accommodate growth in traffic. It is to be used by city staff for the next 10 to 20 years as a guide for improvements.

Ideas to help manage expected traffic growth at the Foothill and Highway 1 intersection include widening the highway to three lanes in each direction from the current two between Highland Drive and Murray Street.

The study also suggests replacing the traffic signal at Foothill with a roundabout or a freeway-style “diamond” interchange.

The suggested projects would cost from $5 million to $20 million.

The city would likely seek state funding to complete the project, said Jake Hudson, traffic operations manager.

“The goal is to pursue a project that can be accomplished as soon as possible in that location,” Hudson said.

“That can be anywhere from five to 10 years from now,” he added. “There is no way of knowing how long it will take at this point in the process.”

Other key findings include the need to improve pedestrian and bicycle crossing at Boysen Avenue and Highway 1.

Cal Poly students and other pedestrians cross Highway 1 there without safety precautions. Suggestions include creating an undercrossing so pedestrians can get from Boysen Avenue to Cal Poly without having to walk along the road’s lanes or slowing traffic.

The council made it clear Tuesday that the Boysen Avenue improvements should be a priority.

The study also found that improvements to the Highway 1 and Highway 101 interchange at Walnut and Olive streets will likely not be needed until 2027.

City staff is expected to begin studying each of the concepts to bring back to the council for more review. The project suggestions would also need Caltrans’ approval.

The study focused on Santa Rosa Street from Walnut Street to Stenner Creek Road and included the Highway 101 interchange north of Walnut Street.

The study area was bounded by Broad and Chorro streets to the west, Cal Poly and California Boulevard to the east, and Monterey Street to the south.