Impact of Variable Speed Limits on Crash Frequency and Crash Rate: Stimulation by Flow Rate and Percentage of Heavy Vehicles
Received: 19 November 2024 | Revised: 27 December 2024 | Accepted: 1 January 2025 | Online: 2 February 2025
Corresponding author: Abeer K. Jameel
Abstract
The current transportation system has faces a high number of crashes on road networks, often resulting in damages and human losses. According to WHO, these incidents cost most countries approximately 3% of their GDP. This underscores the need to address the weaknesses in road networks and provide efficient countermeasures to reduce these incidents and consequent losses. This study focuses on Variable Speed Limits (VSL) as a crucial factor that could influence road safety. To model the impact of VSL on the Crash Frequency (CF) and Crash Rate (CR), the researchers also considered other relevant traffic characteristics, such as the Percentage of Heavy Vehicles (PHV) and Average Daily Traffic (ADT). For the purposes of this research, the Mandali-Baqubah highway in Iraq was selected as a case study for the potential implementation of VSL. The statistical regression approach was utilized to model the Safety Performance Functions (SPF) for the road crash count. The findings of the current study revealed that the VSL are positively and significantly associated with CF and CR.
Keywords:
road safety, Poisson gamma, R project, safety performance function, traffic volumeDownloads
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