Since northbound I-5 opened in downtown Seattle in the 1960s, there’s been two through mainline lanes along this stretch past Seneca Street. Working within our existing roadway, we moved existing barrier and restriped to create a third through lane to try and improve mobility along this section of freeway. We know we can’t improve traffic by just creating lanes, so this is part of a bigger project that includes new ramp meters, additional electronic roadway signs and adding another exit-only lan