This light could tell you if a car is driving itself

The rise of semi-autonomous vehicles and advanced driver assistance systems (ADAS or ADS) has been focused around creating safer roads, and now the US wants to make it easier to identify which cars are driving themselves.

In a proposal by the National Highway Traffic Safety Administration (NHTSA), the regulator has called for carmakers to be allowed to fit cyan-coloured lights to their vehicles, which would let other road users know if the ADAS systems are in use.

“The agency believes that the standardisation proposed here may have some safety benefits, as it would reduce confusion for other road users by making clear that cyan lights mean a vehicle is being operated without the expectation that a human occupant is monitoring the roadway and ensuring that ADS marker lamp implementations do not impair the performance of required lighting,” its proposal reads.

“However, due to several limitations, NHTSA is unable to estimate the potential safety benefits. Given the still-developing nature of this market, NHTSA cannot quantify the number of vehicles that may be affected by this proposed rule. 

“Further, without this regulatory change, NHTSA believes that these vehicles would seek exemptions from this standard, rather than include the unnecessary equipment or, in the case of the ADS marker lamps, not provide additional lighting.”

The proposal doesn’t state what Level of Autonomy vehicles would need to be using for the lights to be activated, however it’s believed that hands-off systems such as Tesla’s Full Self-Driving would be included.

At present, the vast majority of ADAS systems available are Level 2 and require supervision by drivers, which also means the person sitting behind the steering wheel is ultimately responsible for the vehicle if it is involved in a crash.

However, in the US a growing number of companies are rolling out fully autonomous taxis – commonly known as robotaxis – such as Waymo and Tesla, where there is no driver behind the wheel.

Lights denoting ADAS use aren't new, as some Chinese brands have been fitting blue lights to their vehicles in recent years, with the same aim of letting other road users and first responders know who is in control of the vehicles.

Despite this, reports earlier this year suggested the nation would ban the technology, due to a lack of standardised regulations around it, with the blue lights not being an approved colour for road use.

Back in 2023, Mercedes-Benz received approval to run cyan ‘marker lights’ on its semi-autonomous testing vehicles in California and Nevada, ahead of the rollout of its Drive Pilot system.

Australia has yet to see any vehicles in showrooms with ADAS-activated lights.