Evaluating Passenger Transport Emissions and Modal Shift with Elasticity-Based Regional Scenario Tool

Transport is one of the largest emitting sectors of greenhouse gas emissions and to reach climate targets, transport emissions must be reduced. In Finland, 97 municipalities have set ambitious target to reduce greenhouse gas emissions by 80% by 2030 from 2007 levels. Regions and municipalities need tools to evaluate whether their planned measures align with emission reduction targets. This study presents a novel regional scenario tool, specifically designed for estimating the influence of mobility measures on modal shift and, consequently, regional transport emissions. Moreover, the tool takes into account the evolution of regional car fleets, and their impact on regional passenger transport emissions. The effects of various mobility measures are estimated with demand elasticities and diversion factors. The developed scenario tool is demonstrated with two scenarios, which include changes in travel time and travel cost of both private cars and public transport. These alterations were found to result in shifts in modal share and further transport emissions. The results demonstrate that demand elasticities are stronger for travel time compared to travel cost. The tool created in this study is designed to assist local authorities with climate work and decision-making process, thus contributing to the achievement of climate targets.