Impacts of Roadside Vegetation and Lane Width on Speed Management in Rural Roads

Effective speed management in transition areas is crucial. Although numerous studies have proposed countermeasures to ensure driving safety, little research has been conducted on identifying effective and low-cost countermeasures for speed management when transitioning from rural roads to small towns. This study proposes two countermeasures: roadside vegetation and change in lane width and investigates the impact of these countermeasures on speed management performance in this context using a driving simulator experiment. Thirty participants completed eight scenarios, and countermeasures were evaluated based on stabilized speed, minimum speed, and in-town average speed. Results showed that stabilized speed and minimum speed decreased significantly in the combination of narrow lane and different vegetation designs compared to the baseline. Post-countermeasure in-town average speed didn’t decrease significantly in all scenarios. These findings suggest that roadside vegetations and narrow lane width can be effective for speed management in the transition from rural roads to small towns.