Abstract
Transport investment in developed countries (such as bypasses or urban arterial roads) generally result in marginal improvements. Economic development benefits derive mainly from decreased time/money costs of movement. While there is a linkage between transport investments and economic development, the direction of the connection is not always clear. The key question on transport investment is whether the benefits are considered so great that it is worth spending the money. Environmental and safety benefits resulting from a transport investment are not normally assigned an economic value but are important influences on investment in transport infrastructure.