Barton Highway commences at the interchange with Hume Highway northeast of Yass and heads in a southerly direction as a four-lane, dual-carriageway freeway, before narrowing to a two-lane, single-carriageway highway south of the interchange with Yass Valley Way where it meets its old alignment, and continues south through undulating hills to the village of Murrumbateman, before crossing the border into the Australian Capital Territory (ACT) just outside the village of Hall, before eventually terminating at the intersection with Federal Highway and Northbourne Avenue at Lyneham.

The original purpose of the Yass-Canberra Road was to connect surrounding towns to farming locations in the Yass Valley, and later with the newly-established national capital.

[7] The Department of Main Roads, which had succeeded the MRB in 1932, declared State Highway 15 on 19 February 1935, from the intersection with Hume Highway near Yass via Murrumbateman to the border of the Federal Capital Territory (today Australian Capital Territory) at Hall, subsuming the existing portion Trunk Road 56 from Yass to Hall;[3] the southern end of Trunk Road 56 was truncated to meet Hume Highway west of Yass, as a result.

A further section of dual carriageways was completed in December 2002, between Gungahlin Drive and the southern terminus with the Federal Highway.

A$20 million was set aside in the 2006 federal budget for planning and duplication costs associated with the bypass.

[7] Various NSW[17] and Federal[18] governments have committed funding towards improvements to the Barton Highway, including a bypass east of Murrumbateman and a staged duplication to create 33 kilometres (21 mi) of dual carriageways.