Construction and engineering group Costain has received the go-ahead from Surrey County Council to build the first major crossing over the river Thames in nearly 20 years.The crossing between Walton and Shepperton, which is being built as part of a £32.3m scheme, is due to be completed by 2013. It will replace two temporary bridges in the area. Around 34,000 vehicles use the current road bridge on week days, Costain said."The government has agreed to contribute just under £23.9m to the project with the council providing a further £8.5m, which has already been budgeted for," the company added.