Prior to the bridges being built, river crossings were often dangerous in times of rain, which caused bulk freight movement to be prohibitively expensive for most agricultural and mining produce.

Only the high priced wool clip of the time was able to carry the costs and inconvenience imposed by the generally inadequate river crossings that often existed prior to the trusses construction.

[1] Timber truss bridges were preferred by the Public Works Department from the mid 19th to the early 20th century because they were relatively cheap to construct, and used mostly local materials.

It is an Allan-type timber truss road bridge, and has a bascule-type lift span supported on cylindrical iron piers, designed to allow river-craft to pass.

The requirement that local residents pay for half the cost of the bridge "was deplored by the then Mayor of Hay, who was a vocal advocate for the rights and the development of the Riverina region".

The Bascule lift span is a rare feature, and has associational links with the historic river trade, and has much to reveal about late 19th century civil engineering and manufacturing technology.

[1] Carrathool Bridge over Murrumbidgee River was listed on the New South Wales State Heritage Register on 20 June 2000 having satisfied the following criteria.

[1] The place is important in demonstrating aesthetic characteristics and/or a high degree of creative or technical achievement in New South Wales.

Through this, the complete set of bridges gain some social significance, as they could be said to be held in reasonable esteem by many travellers in NSW.

[1] The place has potential to yield information that will contribute to an understanding of the cultural or natural history of New South Wales.

The Bascule lift span is a rare feature, and has associational links with the historic river trade, and has much to reveal about late 19th century civil engineering and manufacturing technology.

[1] The place possesses uncommon, rare or endangered aspects of the cultural or natural history of New South Wales.