A regulatory cap limiting Zoox to 100 robotaxis in Nevada is set to expire September 25, clearing the way for the Amazon-owned company to expand its commercial fleet of custom-built robotaxis in Las Vegas just as competition heats up.

The Nevada Transportation Authority permit that imposed the 100-vehicle cap is set to expire later this month, TechCrunch has learned. An NTA official and a Zoox spokesperson confirmed the change.

Today, Zoox has about 100 custom-built robotaxis — cube-like vehicles that lack steering wheels and pedals — spread across four U.S. cities, including Austin and Miami. The bulk of the fleet is in Las Vegas and San Francisco. Las Vegas remains the only city where Zoox is charging for rides; the company must still obtain a California permit before charging passengers there.

Zoox began charging for robotaxi rides in Las Vegas last month after receiving a temporary exemption from certain federal motor vehicle safety standards from NHTSA. That exemption allows Zoox to deploy up to 2,500 vehicles per year for the next two years.

The timing is critical. In August, the NTA approved three permits that will allow Tesla, Uber, and Waymo to operate commercial robotaxi services in Clark County. Together, the permits could bring up to 7,000 robotaxis to the area over the next 12 months.

Waymo has already launched its robotaxi service in Las Vegas, starting with dozens of its new Ojai minivan robotaxis in a 23-square-mile area including the Strip. Zoox plans to steadily increase its fleet over the coming months "to meet the high demand in Las Vegas and other markets," a spokesperson said.