Taking steps toward healthy & sustainable transport investment: A systematic review of economic evaluations in the academic literature on large-scale active transport infrastructure

For cities seeking to promote active transport, overcoming the institutional practices of car-centric planning and investment is critical to redistributing funds toward dedicated walking and cycling infrastructure. Slowly, urban policy and research are expanding traditional mobility-centric economic evaluations beyond major road and rail projects. This review paper of the academic literature employs a systematic quantitative literature review (SQLR) methodology and contributes an up-to-date examination of academic economic evaluations undertaken on large-scale active transport infrastructure implementations (i.e. capital costs greater than USD$3 million as of 2022). Seventeen (17) peer-reviewed academic papers were included in the final analysis. Cost-benefit analysis (CBA), followed by cost-effective analysis (CEA) and health impact assessment (HIA), were the most common pre-implementation (ex ante) and post-implementation (ex post) assessment methods. Between implementation-types, contexts, and methodologies, the parameters factored in econometric evaluations present a large degree of variance. Despite this, all studies demonstrated the positive return on investment in large-scale active transport infrastructure, where all CBAs produced benefit-cost ratios greater than the breakeven threshold (i.e. >1). Results show health parameters contribute the greatest benefit to positive evaluations, accounting for 77% of total benefits (and 67% in the CBA papers). However, evaluations inconsistently factor or omit long-term, intergenerational, and non-mobility benefits that highlight a partiality in their approach and can be co-opted to support predetermined outcomes. Further research must seek to establish if more expansive, sustainability-orientated methods are needed, or whether to adopt policy positions acknowledging the positive returns walking and cycling infrastructure deliver.