Study: PCH roundabouts would add just 7 seconds to evacuation Play

The two proposed roundabouts on PCH in western Malibu would delay wildfire evacuation traffic by a combined total of about 7 seconds, according to a new city traffic study.

The city council asked for the study to see if the traffic circles would delay evacuating traffic toward Point Mugu.

City traffic engineers estimate it would take 16 hours to evacuate all of Malibu to the west on PCH, whether roundabouts are built or not.

PCH has just one lane in Ventura County. It really doesn't matter if the roundabouts are installed or not. That's the conclusion from Kimley-Horn, the city's traffic engineering firm.

They looked at a complex set of traffic behavior and what is planned.

The study concludes the roundabouts would delay evacuating traffic by 2.9 seconds at El Matador Beach and 4.2 seconds at Encinal Canyon Road.

That is just a tiny blip when compared to the potential delays caused by Southern California Edison intentional power outages, called PSPS. Power outages are expected to add 45 minutes to the evacuation — power outages cause mass confusion and delays at blacked-out traffic signals.

But evacuating Malibu to the west will be a disaster whether the roundabouts are built or not.

Evacuating the entire city to the west, toward Oxnard, would take 16 hours under the disaster scenario imagined by the traffic engineers. That's assuming each vehicle leaves at varying times — a gradual day-long evacuation.

Each driver could expect an average time stuck in traffic of four and a half hours, with the roundabouts contributing 7 seconds of additional time.

Evacuation performance is influenced far more by regional roadway constraints than by the proposed roundabouts, according to the traffic engineers. PCH shrinks to just one lane three miles past the roundabouts, causing a jam heading west no matter if the roundabouts are installed.

The study concludes that the proposed quick-build roundabouts would have minimal impact on overall wildfire evacuation performance and clearance. The study says power outages add 45 minutes to the four hours it would take to get out of the evacuation zone using PCH to the west only.

Malibu's city council has approved the concept — but not the location — of the two roundabouts that the city staff wants to install. The council held off on final approval until they could find out if the roundabouts would delay emergency evacuation traffic.

The answer is: no real additional delays in an emergency, according to the experts.