Yes, road pricing or pay per mile road user charging has been suggested as the most likely way for the Government to recover lost revenue from fuel and road tax, although there's been nothing official from the Government on that.
The House of Commons Transport Select Committee has an inquiry running on it at the moment.
There are various ways road pricing could be done and there are security, privacy and accessibility concerns if mobile phones are used as a means of tracking and paying so the Government will also need to consider physical infrastructure such as toll booths, gantries with cameras etc.