Work

Assessing the limitations of motorization rate as a proxy for local climate-related variables: Evidence from Bulgaria and Sofia

Year: 2026

Type: article

Abstract: This study evaluates whether the number of registered passenger cars (motorization rate) can be used as a standalone proxy indicator for local climate-related variables. Using official datasets for Bulgaria and its capital city, Sofia, over the period 2004–2022, the analysis examines the relationship between vehicle registration counts and two aggregated climate indicators: average annual air temperature and average annual precipitation. Correlation and regression analyses reveal weak and statistically non-significant associations with temperature, along with negligible explanatory power for precipitation. These findings indicate that vehicle registration counts alone are insufficient for explaining or monitoring variation in aggregated climate-related variables. Building on this negative result, the study outlines a methodological framework for future transport–climate research based on activity- and composition-oriented indicators, including vehicle-kilometres travelled, fleet structure, and higher temporal resolution data.

Source: Transportation Research Interdisciplinary Perspectives

DOI: 10.1016/j.trip.2026.101949

Authors: I. Damyanov, G.D. Mladenov, D.N. Saliev, R. Miletiev

Institution: Technical University of Sofia

Language: English

Topic: Energy, Environment, and Transportation Policies

Subfield: Renewable Energy, Sustainability and the Environment

Field: Energy

Domain: Physical Sciences

SDGs: Climate action, Sustainable cities and communities, Industry, innovation and infrastructure

Open Access status: gold

Estimated APC paid: $2,400