The route, part of the traditional Aboriginal pathway network, was shown to Archibald Bell, Jr. by Darug men Emery and Cogy in 1823.

[3][4] Subsequently, he was accompanied by the Government Assistant Surveyor and the route marked was known as Bell's Line, to be later cleared to become the second road across the Blue Mountains.

At Bellbird Hill it then proceeds to climb onto the Bell Range of the Blue Mountains, passing through Kurrajong Heights.

The steepest section is at Bellbird Hill, where the road rises around 450 metres (1,480 ft) from the Hawkesbury Valley to the Bell Range.

In 2002, road-lobby groups secured $2 million in funding for a feasibility study into building a freeway following Bells Line of Road.

The proposed freeway would have linked to the M2 Hills Motorway in Sydney and connected to the Great Western Highway west of Lithgow via a route across the Newnes Plateau.

It is also revisiting studies last undertaken in the 1960s to extend the planned Castlereagh Freeway (subsequently partly-built as the M2) to connect with Bell's Line of Road at Kurrajong Heights.

If this project were to be implemented it would force major improvements to be undertaken to the route followed by Bell's Line of Road, due to the traffic volumes that would be generated by a freeway.