Governor Brown’s pet transportation bill that was just approved sealed the deal for higher diesel fuel taxes and required some horse trading with truckers seeking stability in fleet vehicle requirements for the future.  It’s a familiar path in California – one with mixed results.

The state that leads the nation in electric car registrations last year ranked 47th of 50 for adoption of the latest in low-emission commercial truck technology.  Around 23 percent of the largest tractor-trailer size commercial trucks in California are of the newest and cleanest generation, compared with a national average of 30 percent. Only Alaska, Maine, Arizona and Kentucky rank lower.

The high population of older vehicles is significant because California’s federal ozone non-attainment status – while improving – still falls consistently short.  The primary culprit cited by clean air regulators is nitrogen oxide (NOx) emissions from these older diesel trucks which regulators say must be drastically reduced to meet ozone standards.

Several factors likely contribute to the low penetration of new technology vehicles. The most notable is a set of California Air Resources Board rules that require all trucks registered in the state be 2011 model year or newer by 2023.  Diesel engines power well over 90 percent of the fleet with the newest versions having 90 percent fewer emissions than older models.

This means, for about the next six years, many older, higher-emitting trucks – though still perfectly legal –will traverse California’s roads, delivering the daily goods and services needed by Californians.  Some of the oldest trucks have 60 times the emissions of a new diesel truck, but all support the livelihood of thousands of independent truckers and small businesses.

Now there’s a golden opportunity for California to take immediate and meaningful steps to address the very issue it so often espouses – reducing these NOx emissions. The new opportunity comes in the form of $423 million from the Environmental Mitigation Trust included in “Appendix D” of the Volkswagen emissions settlement.  It’s important to note that Trust funds are for offsetting emissions generated from the operation of the VW vehicles in violation, not to advance other technology agendas.

Applying settlement funds to accelerate the repowering of the very largest and oldest trucks or industrial marine and locomotive engines with new technology would yield immediate and significant NOx benefits, and do so at the lowest cost per ton.  Some clean diesel options are 200 times or more cost-effective at reducing NOx than other alternative fuel strategies. Communities located near freight corridors such as those along the I-710 freeway and congested urban areas with the highest ozone levels bear the largest burden. They shouldn’t have to wait for cleaner air when these cleaner trucks are available right now.

State air regulators have said the fastest reductions in NOx emissions in 2035 won’t come from power plants or even the electrification of passenger vehicles, but rather from the turnover of older commercial trucks powered with the latest clean diesel engines.  It’s a proven strategy, as evidenced by the Ports of Los Angeles and Long Beach Clean Truck Programs that moved truckers to newer technology so quickly that port pollution was reduced by 70 percent in only one year.

As for California’s vision of future electrification, it is well funded thanks to an additional, exclusive $800 million from another part of the VW settlement to be paid out over the next 10 years.  But those investments won’t pay significant clean air dividends for decades, especially along freight corridors.  In contrast, the newest and cleanest diesel engines, trucks and machines are on dealer lots today.

Accelerating the turnover of older commercial diesel trucks and heavy-duty rail and marine engines to newer models is a proven strategy to mitigate NOx emissions.   California policymakers know that. It’s what they’ve been saying for years.

It’s a strategy that can yield more clean air for the dollar and deliver it faster to more people. Now it’s time to get it done.

(Allen Schaeffer is the Executive Director of the Diesel Technology Forum, a non-profit organization located in Frederick, MD, that is dedicated to raising awareness about the importance of diesel engines, fuel and technology. For more information visit