We often think about electrifying the vehicles that carry people and heavy loads up and down our roads, like cars, transit buses, big rigs, school buses, and garbage trucks. There’s good reason for this: these vehicles pump out a hefty portion of our transportation pollution in California. But to achieve our goal of truly clean air, we need to electrify everything. This means we need to shift zero emission ambitions beyond our roads to the equipment and machinery operating off the road.

There is a whole world of off-road equipment. These machines literally operate on other terrains—anywhere but on our roads. These sometimes-forgotten pieces of equipment include construction and farming machinery like bulldozers, tractors, compactors and trenchers, and all kinds of trains, like passenger, freight, and industrial rail.

Off-road equipment is heavily polluting, generally burning one of the dirtiest fuels around: diesel. In fact, off-road mobile machinery makes up about 35% of all statewide transportation pollution. Electrifying this equipment is an essential steppingstone on the path to a zero-emissions future. We can’t clean up California’s air if we don’t clean up off-road equipment.

Thankfully, a historic hearing this week at California’s air agency will get us that much closer to protecting our lungs and the climate. The California Air Resources Board (CARB) is hearing three important items that will return big benefits to Californians: the Off-road Rule, Locomotive Rule, and a record-setting $2.6 billion clean transportation funding plan. If approved, these items will require some of the dirtiest, most outdated equipment in California to clean up fast and create a huge pot of funding to support the transition.

A look at the health benefits expected to flow from the Off-road and Locomotive Rules gives a sense of their sheer magnitude. Together, these two regulations would prevent close to 4,000 premature deaths, avoid more than 1,300 hospitalizations for cardiovascular or respiratory illness, and offer Californians a whopping $40 billion in health benefits. These stringent regulations will reduce statewide NOx emissions by 430,000 tons.

These benefits translate to lives changed and families protected from the devastation of respiratory illness and heart problems. On top of this, it would be almost impossible to recover these health wins and emission reductions for Californians without these requirements.

So, what would these regulations do?

The Off-road Rule hastens the timeline for when the most antiquated, diesel-spewing off-road equipment must be put to rest in California. The regulation also charts a healthy path to zero emissions by requiring dirty equipment be replaced with less-polluting models. There will be continued work to shift these fleets to zero emissions, but we are on the right path.

The Locomotive Rule takes a similar two-step approach. One of the greatest challenges with cleaning up trains is that they can continue to operate for decades—sometimes up to 60 years. While seemingly innocuous, this means that the most archaic technology can spew toxic fumes alongside our homes and schools for decades. California’s rule would put an end to this by requiring all trains operating in California for 23 years to retire unless they are zero emissions, beginning in 2030.

At the same time, CARB is charting an end to combustion trains in California. By 2030, all new passenger, industrial, and railyard trains must be zero-emissions. All new long-distance locomotives must have zero-pollution by 2035.

The Off-road and Locomotive Rules would be major milestones not only for California’s transition to a cleaner future, but for the entire nation. If California adopts these rules, other states are permitted under the federal Clean Air Act to follow suit. Regulations like these are the only sure way to hold industry accountable for zeroing out emissions from their own equipment, so the implications of this could be huge.

While financial incentives are no replacement for emission-reducing mandates, they can help grease the wheels by supporting fleets, manufacturers, and purchasers with rebates and price cuts during this period of transition.

The Board will also vote on whether to approve a record-setting $2.6 billion investment in clean transportation. Not only is this the largest pot of zero emissions transportation funding in California history, but when combined with the groundbreaking levels of federal investment via the Inflation Reduction Act and the Bipartisan Infrastructure Bill funding, we are facing a truly monumental level of funding for a zero emissions future.

The California Air Resources Board has a landmark opportunity at the hearing this week to push forward on zero emissions rail and off-road vehicles. These new zero emissions policies are key moments where the rubber hits the road (and terrain, field, and turf) in shaping a future with clean air and a protected climate.