The launch of the EV maker’s robotaxi service would cap a decade of promises about autonomous vehicles by Tesla CEO Elon Musk.

Tesla investors have been eagerly awaiting the start of the company's robotaxi service as it attempts to catch up to other autonomous vehicle companies — such as Waymo, which already offers a driverless ride-hailing service in Austin and some other cities in partnership with Uber.

In a letter signed Wednesday, a group of Democratic lawmakers asked Tesla to delay the launch until Sept. 1, when new safety guidelines for autonomous vehicles go into effect.