Contrary to common perceptions, investments in public transport may often give positive outcomes in cost-benefit analyses. Success factors include:
- limited project scope: the main goal should be to remove traffic bottlenecks, with no additional, external investments;
- projects should be implemented within or between densely populated areas;
- the project should be flanked with ancillary (e.g. parking) policies.
Public transport projects would probably measure up even better in cost-benefit analyses if noise, emissions and (especially) road safety were valued more satisfactorily. Calculations might also be extended to include the spatial and social benefits of public transport projects, using for example an appropriate spatial efficiency indicator.