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修改/美化 80字英文
Double decker bridges exist to serve different purposes by providing two road levels. Most have four to six lanes of motor traffic on the upper deck while the lower deck has cycling and walking tracks. There are also bridges that provide special amenities such as the tower of Novy Most Bridge in Bratislava which houses a restaurant. This increases the building cost of such bridges.
Budget does not always consist of the construction costs alone. For instance, in site preparation there are the demolition costs for existing infrastructures or edifices , and the compensation paid to existing landlords.