Many cities have adopted signal coordination schemes to improve the operational efficiency of arterials. Through providing a “green wave”, the coordinated signals allow vehicles to pass consecutive intersections with fewer stops. Conventionally, studies focused mainly on the efficiency aspect of signal coordination. From a safety perspective, there are few studies devoted to investigating spatial heterogeneity and homogeneity simultaneously along arterials, particularly those with different traffic control and signal coordination schemes. Applying a joint negative binomial conditional auto-regression crash sum (JNBCS-CAR) model, this paper aims to comprehensively evaluate traffic safety on arterials with coordinated traffic signals. The performance of JNBCS-CAR is compared to those of traditional five ones (i.e., Poisson log-normal (PLN), negative binominal crash sum (NBCS), Poisson log-normal conditional auto-regression (PLN-CAR), negative binominal conditional auto-regression crash sum (NBCS-CAR), and hierarchical Poisson log-normal conditional auto-regression (HPLN-CAR)). Nine years of data are selected from the City of Ann Arbor (Michigan). Results indicate that (1) the JNBCS-CAR model outperforms other models in terms of the goodness-of-fit; (2) signalized intersections appear to have significant spatially heterogeneous effects on roadway segments under the scenario of signal coordination, while roadway segments do not have spatially heterogeneous effects on signalized intersections; and (3) there is a strong spatially homogeneous correlation among the coordinated intersections, but not among the segments. The findings serve to provide an accurate evaluation of the coordinated signalization from the safety perspective.

许多城市已经采用信号协调方案来提高动脉的运营效率。通过提供“绿波”，协调信号使车辆能够以更少的停车位通过连续的十字路口。传统上，研究主要集中在信号协调的效率方面。从安全的角度来看，很少有研究专门研究沿动脉的空间异质性和同质性，特别是那些具有不同交通控制和信号协调方案的研究。本文应用联合负二项式条件自回归碰撞总和（JNBCS-CAR）模型，旨在对交通信号协调的道路交通安全性进行综合评估。将JNBCS-CAR的性能与传统5种性能（即泊松对数正态（PLN），负二项式碰撞总和（NBCS），泊松对数正态条件自回归（PLN-CAR），负二项式条件自回归碰撞总和（NBCS-CAR）和分层Poisson对数正态在条件自回归（HPLN-CAR ））。从安阿伯市（密歇根州）中选择了九年的数据。结果表明：（1）JNBCS-CAR模型在拟合优度方面优于其他模型；（2）在信号协调的情况下，信号交叉口似乎对道路段具有明显的空间异质性影响，而道路段对信号交叉口则没有空间异质性影响；（3）协调交叉点之间的空间同质性相关性很强，但路段之间则没有。