(Reuters) – The Trump administration proposed on Monday rules that would allow drones to operate over populated areas and end a requirement for special permits for night use – long-awaited moves that are expected to help speed commercial use of small unmanned aerial vehicles in the United States.

U.S. Transportation Secretary Elaine Chao was outlining the proposal, which will be open to public comment before it can be finalized, at a speech in Washington.

Alphabet Inc and Amazon.com Inc are among a growing number of companies hoping to make package delivery by drones a reality.

The Federal Aviation Administration said that in developing the proposal its challenge was to “balance the need to mitigate the risk small unmanned aircraft pose to other aircraft and to people and property on the ground without inhibiting innovation.”

The FAA is proposing ending requirements that drone operators get waivers to operate at night. Through 2017, the FAA granted 1,233 waivers and “has not received any reports of (drone) accidents,” it said.

The FAA would require drones have “an anti-collision light illuminated and visible for at least 3 statute miles.”

For operations over populated areas, the FAA proposes that operators would be able to fly small unmanned aircraft weighing 0.55 pounds (0.25 kg) or less without any additional restrictions.

But the FAA would set additional rules for larger drones.

For drones weighing more than 0.55 pounds, a manufacturer would need to demonstrate that if an “unmanned aircraft crashed into a person, the resulting injury would be below a certain severity threshold.”

Those larger drones could not have exposed rotating parts that could lacerate human skin and could not operate over people if they have any safety defects, the FAA said.

The FAA would prohibit operations of the largest drones over any open-air assembly of people.

In 2017, President Donald Trump launched a program to expand testing of drones in what the White House said would “open the skies for delivery of life-saving medicines and commercial packages (and) inspections of critical infrastructure.”

Separately, the FAA said Monday it was considering moving ahead with additional rules in response to public safety and national security concerns as it works to integrate drones with airplane traffic.

The FAA is also proposing allowing discretionary waivers for operations over moving vehicles, for operations over people that would not otherwise meet the standards outlined in its proposal, and for those that do not meet its anti-collision lighting requirement.

Drone safety issues remain a concern.

Two London airports have been disrupted by drones in recent weeks and the British government is considering toughening laws that ban the use of drones near airports.