The highways splits into a one-way pair in downtown Fort Smith with northbound running along B Street and southbound Highway 255 following A Street.

In Seattle, the southbound Highway 99 exit for Battery street exits onto the left side of the roadway, with Battery street becoming one way on the right side going NE.

The loop ramp from Highway 410 southbound to Highway 401 eastbound was replaced by a semi-directional high-speed flyover, while a new directional ramp and semi-direction flyover were added to serve westbound 401 commuters.

The flyover ramp which connects southbound Highway 427 with eastbound Highway 409 was constructed in the early 1990s.

The highway is crossed by Baseline Road and Richmond Road; the former provides an onramp to southbound Highway 416.

Despite its size, there is no ramp to provide access from southbound Highway 427 to eastbound Highway 401.

From that point, it would be an easy two-mile run to pick up Highway 66 due west, or southbound Highway 495.

In the late hours of morning on May 21, 1976, a bus filled with the school's choir veered off the Marina Vista/Martinez Exit off-ramp off southbound Highway 680 (Now Interstate 680), fell approximately 30 feet, and landed on its roof, crushing the roof towards the bottom.

The traffic jam is also caused by the configuration of the junction of southbound Highway 5 with eastbound Autoroute 50 where there is only one lane of traffic to access the 50 and traffic must change lanes immediately.

After this, the opposing directions of travel diverge and become ramps to northbound and from southbound Highway 416.