August 17, 2010
Commentary: The Need for Truck Lanes
Why Truck Climbing Lanes?
By Victor Lindenheim
Golden State Gateway Coalition
Designated truck lanes, also called truck climbing lanes, are designed to improve freeway operations by providing additional throughways for trucks and other slow-moving vehicles that face challenges on steep grades, especially in congested areas where they are competing for space with other vehicles.
By separating large, slow-moving trucks from other vehicles, designated truck lanes greatly ease overcrowded roadways, increase mobility, improve air quality and enhance goods movement. By design, the beginnings and ends of designated truck lanes are generally long enough to allow for the weaving of traffic so there is no congestion caused by the truck lane itself.
The Interstate 5 Santa Clarita-Los Angeles Gateway Project proposes the addition of one northbound and two southbound truck lanes along the I-5 between State Route 14 and the Pico/Lyons Interchange in north Los Angeles County. There are no adverse merging or diverging impacts from this project.
In the southbound direction, each of the truck lanes begins by starting a new lane where existing on-ramps exist (Pico/Lyons and Calgrove). Trucks simply move over to the right to begin travel in the designated truck lanes. Near State Route 14, these downgrade southbound truck lanes will connect into existing separated truck lane facilities. Because the proposed southbound truck lanes are not barrier-separated, there are several miles to allow the weaving of traffic without causing additional congestion.
In the northbound direction, there are existing truck lanes that currently end and merge with a mixed-flow lane. This is an upgrade that also merges with traffic coming off of State Route 14 from the east. The proposed northbound truck lane would extend the existing truck lane up and over the hill and end at the Calgrove off-ramp. The project, therefore, moves the merge point of the truck lanes away from the current merge point with SR 14 traffic and also allows the trucks to merge on the downgrade before Calgrove Boulevard. when they should be up to the speed limit. There would be no additional congestion created by this proposed truck lane project in either direction.
The Interstate 5 Santa Clarita-Los Angeles Gateway Project also proposes the extension of existing high occupancy vehicle (HOV) lanes for about 13 miles within the I-5 median starting from the I-5/SR-14 Interchange. While the truck climbing lanes alone will provide significant congestion relief, extension of these HOV lanes will be critical to long-term traffic congestion relief during peak hours.
Thanks to Eileen Reynolds and Tony Harris for technical assistance on this column.