WASHINGTON, April 26 (Reuters) - Two U.S. senators on

Friday urged regulators to bar Tesla from allowing the

use of driver assistance system Autopilot on roads where it is

not intended.

Democratic Senators Ed Markey and Richard Blumenthal said

the National Highway Traffic Safety Administration should

"require Tesla to restrict its Autopilot feature to the roads it

was designed for. We urge the agency to take all necessary

actions to prevent these vehicles from endangering lives."

The auto safety agency said on Friday it is opening an

investigation into the adequacy of Tesla's December recall of 2

million vehicles to boost Autopilot safeguards.