AEB proposal to begin public comment period

July 5, 2023

Mark Schremmer


A proposal to require automatic emergency braking systems on heavy vehicles is scheduled to publish in the Federal Register on Thursday, July 6.

Once that happens, the public will have 60 days to comment on the joint notice of proposed rulemaking from the National Highway Traffic Safety Administration and the Federal Motor Carrier Safety Administration.

The two agencies announced the proposal, which would require AEB systems and electronic stability control systems on new vehicles that weigh more than 10,000 pounds, at a news conference on June 22. The proposed standard would require the technology to work at speeds ranging between 6-50 mph.

According to the notice, the proposal would prevent 19,118 crashes, 155 fatalities and 8,814 injuries annually.

“Advanced driver assistance systems like AEB have the power to save lives,” said Ann Carlson, NHTSA’s chief counsel, at the June 22 news conference. “Today’s announcement is an important step forward in improving safety on our nation’s roadways, and ultimately eliminating, preventable tragedies that harm Americans.”

The 2021 infrastructure law required NHTSA and the Federal Motor Carrier Safety Administration“to conduct a review of automatic emergency braking systems used in commercial motor vehicles and address any identified deficiencies in the rulemaking.”

Truck safety groups praised the proposal for going beyond Congress’ orders.

“Humans are fallible,” Truck Safety Coalition Executive Director Zach Cahalan said in a news release. “Sometimes truck drivers are distracted or fatigued. AEB is effective even when humans make mistakes. This is a slam dunk for roadway safety.”


Those opposed to mandating automatic emergency braking systems contend that the technology has not been perfected and point to reports of false braking, issues regarding inclement weather and negative feedback from drivers.

Opponents also question the timing as just about a month ago, NHTSA opened an investigation into false automatic braking on certain Freightliner and Western Star trucks.

There were 18 complaints of false automatic emergency braking activation “without an actual roadway obstacle.” In some instances, the false activation brought the truck to a complete stop in the travel lane. NHTSA did not report any crashes caused by the false braking.

The investigation aims to determine if the alleged defect creates an unreasonable safety risk.

The agencies also acknowledge in the notice of proposed rulemaking that the unintended consequences of false activations “cannot be quantified.”

In addition, Daimler recently announced that it is recalling about 330 eCascadias over a problem with the electronic stability control. The issue can lead to insufficient braking force when activated.

OOIDA, which opposes an automatic emergency braking system mandate, says that the agencies must resolve any performance issues before attempting to move forward.

“We are always going to have concerns about regulatory mandates for technology or any other rulemaking that hasn’t been proven to benefit highway safety,” said Jay Grimes, OOIDA’s director of federal affairs.

Grimes added that OOIDA has heard concerns from drivers about false activation, taking control out of a driver’s hands and not being able to work properly in all weather and road conditions.

“This proposal is being announced and released at the same time some of the studies for AEB on commercial vehicles are ongoing and haven’t been completed,” Grimes said.

What’s next?

Starting July 6, the public will have two months to comment on the proposal. The agencies will then use those comments to determine whether to issue a final rule.

If the proposal eventually becomes a final rule, all Class 7 and 8 vehicles – those weighing more than 26,000 pounds – would be required to meet the automatic emergency braking standards three years after the rule takes effect. All Class 3-6 vehicles – those weighing 10,001-26,000 pounds – would be required to meet the automatic emergency braking and electronic stability control requirements in four years. Small-volume manufacturers would have until five years after the final rule took effect. The proposal would not require existing heavy vehicles to be retrofitted with automatic emergency vehicle technology. LL