Is a dedicated bus lane operationally and environmentally beneficial? A case study in Beijing

In 2023, Beijing adjusted dedicated bus lane (DBL) policies, allowing private car access during specific periods to improve road transport efficiency. This study proposes a comprehensive method to assess the operational and environmental impact of DBL adjustments. Traffic volumes are estimated using a localized traffic fundamental diagram model based on large-scale floating car speed data, while vehicle emissions are quantified employing a high-resolution road network emission inventory. Results show over 20% increased traffic volumes and 10% higher average speed on DBLs in central Beijing. Extended to regional road network, the adjustments enhance expressway capacity and improve traffic efficiency on main and minor arterial roads. While total emissions on expressways increase due to heightened traffic volumes, average vehicular emission intensities in urban areas decrease because of smoother traffic flow. These findings could provide valuable insights for decision-makers with the information needed to target reasonable DBL policies in metropolitan regions.