Inside Seven
Current Issue: September 2014
District 7’s system is the most utilized HOV system in the nation, with 331,000 vehicles (780,000 people) using it every day.

District 7 Reaches HOV Milestone: 500 Lane Miles and Counting!
by  Kelly Markham
Issue Date: 07/2010

They say diamonds are forever. Diamond lanes might be as well. High-occupancy vehicle lanes remain one of the most powerful congestion-busting strategies we have.

[Click on photos to read captions.]

HOV lanes. Carpool lanes. Diamond lanes. Commuter lanes. High occupancy vehicle lanes. Whatever you call the freeway lanes requiring carpools of two or more people, they’ve become a defining part – and an increasingly crucial part – of District 7’s transportation infrastructure. This summer, with the completion of the Pomona Freeway (SR-60) HOV Lane Project (I-605 to Brea Canyon Road), District 7’s HOV lane system will reach an important milestone: 500 lane miles.

It’s taken 34 years to get here. We can thank the 1970 amendment to the Clean Air Act, which set higher standards for air quality, for jump-starting the HOV system. We got our first HOV lane in 1976, when the El Monte Busway, originally a bus-only facility, began allowing vehicles with three or more people.

That same year, an HOV experiment on the Santa Monica Freeway (I-10) stalled the program for about 15 years. A mixed-flow lane was converted to a three-person carpool lane. The result: the mixed-flow lanes were extremely congested and the HOV lane looked empty. Public outcry ensued, and the scorned HOV lane was converted back to a mixed-flow lane.

Winning Hearts, Minds and Carpools

Suffice it to say, HOV lanes were not an easy sell when they were first introduced. Some people questioned whether HOV lanes actually relieve congestion. (Yes, they do.) Others charged that they would compromise safety. (No, they don’t.) And a small segment of the population believed the right to use any freeway lane at any time is a founding principle of our democracy. (Not so much.)

The tide began to turn for HOV lanes in the early ‘90s. In part, the expansion was due to the Intermodal Surface Transportation Efficiency Act, enacted in 1991, which revised many federal requirements related to transportation planning. A year later, the Los Angeles County Transportation Commission (LACTC, the predecessor of the Los Angeles County Metropolitan Transportation Authority, or Metro) adopted a “Carpool Lane Plan” for Los Angeles. LACTC and Caltrans agreed to develop the HOV system, promising to dedicate $100 million a year to plan, design and construct HOV lanes. Just five years later, the Los Angeles County HOV system had grown from 32 to 269 lane miles.

Fast forward to today. District 7’s 492 HOV lane miles (not counting the new lanes on SR-60) represent 34 percent of all HOV lanes in California. District 7’s system is the most utilized HOV system in the nation, with 331,000 vehicles (780,000 people) using it every day. An average HOV lane in Los Angeles County carries 1,300 vehicles per hour during peak periods. Some carry more than 1,600. The federal minimum threshold is just 800 vehicles per hour.

“When we first started, we used to get a lot of letters and phone calls from the public and elected officials,” said Dawn Helou, Chief of HOV Operations Branch. “We had to combat a lot of the negative criticism and develop performance measures, such as duration of congestion, travel times, the number of people in cars, and 24-hour volumes. The analysis and comparison between the HOV lanes and regular lanes is impressive and convincing. Hardly anyone opposes HOV lanes anymore.”

Reasons to Love HOV Lanes

If you carpool, you already know how much time HOV lanes can save. But even solo commuters benefit from HOV lanes. Picture a five-lane freeway – one HOV lane and four mixed-flow lanes. That one HOV lane carries 34 percent of the people using the freeway. The mixed-flow lane next to it carries only 17 percent. Eliminate the HOV lane and all those carpools (plus the people who decide to drive alone since there’s no HOV incentive) will be in the mixed-flow lane. Traffic speeds will drop significantly for everyone.

The data also show that HOV lanes do encourage carpooling, which results in reduced congestion and better air quality. Between 1992 and today, on freeways with HOV lanes, carpooling has steadily increased. On freeways without HOV lanes, carpooling has remained relatively constant or decreased.

One of the most common complaints about carpool lanes from motorists is that freeway congestion persists even after HOV lanes are added. Indeed it does, but the duration and severity of congestion in the mixed-flow lanes decline substantially.

“We did a lot of studies in the first two years after we added HOV lanes on the I-210 and the I-405 through the Sepulveda Pass,” said Helou. “What we found is that after about 18 months of traffic stabilization [during which motorists adapt to the HOV lane], the previous four hours of congestion was reduced to one hour, which hasn’t been the case on many freeways in Los Angeles since the 1960s.”

HOVering Into the Future

On some freeways, even the HOV lanes are becoming congested. Consequently, Caltrans is implementing innovative HOV strategies to improve traffic flow. Examples include HOV lane ramp metering, adding a second HOV lane on I-10, and coming in 2012, high occupancy toll lanes (aka HOT lanes), which are HOV lanes with a twist: vehicles that don’t meet the carpool requirement can buy their way into them, if space is available.

When talking about the benefits of HOV lanes, it’s easy to get bogged down in the stats: capacity, congestion duration, vehicles per hour, percentage of carpools, etc. But ultimately, HOV lanes address a quality of life issue that’s more difficult to quantify, one that impacts how people feel about the city they live in – the frustration of spending so much time sitting in traffic.

HOV lanes are one of Caltrans’ most powerful tools to combat that frustration, and they’ll continue to be a vital part of District 7’s infrastructure. The 30-year HOV plan calls for the completion of the system in 2025, at which point District 7 will have about 900 HOV lane miles. If you’re keeping track, that’s 500 down, 400 to go.

Currently, District 7 has 492 HOV lane miles. When complete in 2025, the HOV system will have 900 lane miles. This summer, with the completion of the Pomona Freeway (SR-60) HOV Lane Project (I-605 to Brea Canyon Road), District 7’s HOV lane system will reach 500 lane miles. Additional HOV projects will begin on I-5 north of SR-134 this summer. Pictured: the ongoing I-5/SR-14 Direct HOV Connector Project, expected to complete in the fall of 2012. Drivers in low-emission vehicles (e.g., hybrid and electric cars) with a DMV-issued Clean Air Vehicle Sticker can use HOV lanes through January 1, 2011.