关键词: 交通运输工程；城市主干路；交通安全分析；中观；交叉口间距；路网形态

Abstract: The traditional safety analysis model was established at the micro level, which decomposed the adjacent intersections and road sections into two independent research units to study. In dense road network, the distance between intersections of urban arterials was small, and the traffic operation of adjacent sections and intersections affected each other, so it was difficult to divide sections and intersections. Intersection spacing and road network morphology on both sides of the road were important factors affecting the safety of urban arterial. The traditional model studied the road section and intersection accidents respectively, which could not analyze the impact of these two factors on the overall safety of the urban arterial. Based on 21 urban arterials in Shanghai, the adjacent sections and intersections were combined into 118 meso-units according to the road cross-section and traffic operation characteristics, and the road network morphology of the roads on both sides of the meso-units was calculated. Considering the correlation between geometric design and traffic characteristics of meso-units from the same urban arterial, a negative binomial model with random effects was established. The influence of intersection spacing and road network morphology on the safety of urban arterial was analyzed. The results show that compared with irregular grid road network and mixed road network, the number of accidents of urban arterial in grid road network is less; the longer the distance between intersections, the less the accidents on the main road. The meso-level analysis method overcomes the problems of unit division and influencing factor analysis in traditional safety analysis model, and provides suggestions for urban arterial design and road network planning.

Key words: traffic and transportation engineering; urban arterial; traffic safety analysis; meso-level; intersection spacing; road network morphology