Sunset & La Cienega and Santa Monica & Doheny have the biggest estimated peak-hour traffic delays among intersections on West Hollywood’s Westside. That is according to a report by WeHo by the Numbers based on three recent traffic studies.
Consultants prepared the traffic studies as part of the city’s review of three proposed developments: the Robertson Lane Hotel, the 8555 Santa Monica mixed-use project and the Arts Club on Sunset. One of the primary goals of the studies was to determine whether the projects would have a significant long-term impact on traffic at nearby intersections.
The city gets to define what “significant” means. West Hollywood has chosen specific thresholds based on traffic delays caused by a project. In most cases, it is the extra delay for the average driver in one of the peak hours. It has to be at least 8 to 12 seconds for congested intersections of two commercial corridors and 5 to 8 seconds for other congested intersections.
The studies found significant impacts at only two intersections, based on computer models and the city’s thresholds. The first is Santa Monica and Robertson, because of the Robertson Lane Hotel. Without mitigation, the project is expected to add 12 seconds of delay for the average car going through the intersection in the mid-day peak and 25 seconds in the p.m. peak. With that extra delay, the intersection would be graded F (on an A-to-F scale) for its level of service in the p.m. peak. The consultants believe they have identified a mitigation measure that can more than offset the hotel’s impact.
The second intersection is Holloway and Hancock, due to the 8555 Santa Monica project. The project would add 10 seconds of delay for drivers on Hancock in the evening peak. However, the report suggests this may have more to do with the intersection and the calculations than the specific project. The consultant’s computer model says that, in the future, turning from Hancock onto Holloway will be much more difficult in the evening peak. Under those conditions, even one or two extra vehicles from the project making that turn would be significant according to the city’s criteria. The consultant believes the impact is unavoidable.
As part of their analysis, the three studies estimated current peak-hour delays at many Westside intersections. The report compiles those numbers, using averages for intersections with multiple estimates.
The intersection at Sunset and La Cienega has the highest estimate: close to three minutes (166 seconds) of delay for the average driver in the p.m. peak. Santa Monica and Doheny and Santa Monica and Westbourne come next on the list. The Santa Monica and Doheny intersection has over two minutes of delay in the a.m. peak. Santa Monica and Westbourne has an average delay of one-and-a-half minutes in the p.m. peak.
The delays can be represented as level of service (LOS) grades from A to F. Sunset and La Cienega, Santa Monica and Doheny, and Santa Monica and Westbourne are LOS F based on current estimated delays. Two more intersections – Sunset and Doheny and Sunset and San Vicente – were assumed by the consultants to be LOS F because of in-person observations. LOS F is defined as: “Failure. Backups from nearby locations or on cross streets may restrict or prevent movement of vehicles out of the intersection approaches. Tremendous delays with continuously increasing queue lengths.”
The LOS E intersections are La Cienega at Fountain, at Holloway, at Santa Monica and at Melrose, based on the delay numbers. LOS E is defined as: “Poor. Represents the most vehicles intersection approaches can accommodate; may be long lines of waiting vehicles through several signal cycles.”
For more about current and future traffic delays, read the full report, What do recent traffic studies tell us about West Hollywood?