While you might be aware that the toll to cross the Tamar Bridge is £1.50 for your car, have you ever wondered how much the bridge itself is worth?

That was the question for external auditors of Cornwall Council who asked for a new assessment after raising concerns about the valuation of the council’s land and buildings.

Auditors Grant Thornton, in their annual audit findings report for the council, state that the council estimates that its land and buildings to be worth more than £1.5 billion.

The firm is now undertaking a report on the valuation of property, plant and equipment owned by the council. The Tamar Bridge was due to be revalued in April but the auditors found that had not yet been completed.

They challenged the value that the council had put on the bridge as it had not been revalued for four years. The council has a policy of revaluing its land and buildings on a rolling five year basis.

In their report to the council Grant Thornton said it asked the council’s management expert AECOM for its valuation and also employed its own valuer to carry out an assessment.

“Our valuer has concluded that the base value of the bridge, according to AECOM experts is £107m. In addition to this £7m has been spent on enhancements to the bridge in year. Providing an estimated value of £114m.”

Tamar Bridge is jointly owned by Cornwall Council and Plymouth City Council so the council accounts for half of the amount of the value.

But Grant Thornton found that Cornwall Council has over estimated the value of the bridge.

It states: “The bridge is currently in the balance sheet at a value of £60m – ie £120m in total. This therefore gives rise to estimation uncertainty for Cornwall of £3m.”

In its recommendation Grant Thornton said the council  should base its new valuation on the assessment of specialist engineers and that specialist valuers are used to value the bridge in future.