On-demand robotic flying taxis and drone deliveries are years away from reality, but the U.S. Department of Transportation has removed at least one barrier to their operation.

Responding to work by companies including Boeing Co., Intel Corp. and Uber Technologies Inc., the department on Friday said it would use the same process to consider approval of drone taxis that would carry passengers and cargo for hire as it does for approving traditional commercial air carriers.

Amazon.com Inc. and Alphabet Inc.’s Google unit are both developing drones to deliver products.

Under U.S. law, the agency must certify that any business carrying people or cargo for hire is economically “fit, willing and able” to perform. Certifying an airline under those regulations can take years, but the DOT can exempt operators that are using smaller or mid-sized aircraft, it said in a notice set to be posted Monday in the Federal Register.

The Federal Aviation Administration still must approve of a drone air carrier’s safety in a separate process, the DOT said. While the FAA has allowed routine commercial small-drone operations since 2016 — typically for devices weighing less than 55 pounds (25 kilograms) and used for tasks like land surveying or videography — it hasn’t developed safety standards for devices designed to carry people.

Multiple aviation and technology companies ranging from aviation giants like Boeing to technology startups are working on aircraft designs that could be used as robotic taxis, capable of landing on urban rooftops to pick up passengers who want to avoid traffic. Intel’s Chief Executive Officer Brian Krzanich made a test flight last December in a company-built drone, known as a Volocopter, last December.