Socio-economic appraisal of transport investments and transport policies is broadly accepted as a valuable, often indispensable input to decision-making, although opinions differ as to its precise role and there is debate on whether the standard toolkit is up to the task in all cases. An important concern is that applying standard methods of appraisal, which focus on direct benefits for transport users, may produce inaccurate estimates of total benefits. Standard methods are also of little help in gauging the ultimate distribution of project benefits and costs or for estimating impacts on overall output (Gross Value Added) and employment. The issues are particularly pressing for “major projects” – projects with potentially wide-ranging effects outside the narrow transport perspective that lies at the core of standard cost-benefit analysis.