An Integrated Design Framework for Safety Interventions on Existing Urban Roads—Development and Case Study Application

Abstract

The need for improving urban road safety, livability, and sustainability is evident. Quantitative estimates and qualitative methods/strategies can be used by road safety practitioners to design safety interventions. This study proposes a flexible integrated design framework for safety interventions on existing urban road segments and intersections that integrates quantitative and qualitative methods. The proposed design framework is divided into four stages of the safety management process: End of Network Screening, Diagnosis, Selection of Countermeasures, and Economic Assessment. Pilot applications of the proposed method were performed on existing roads of the urban road network of the Municipality of Bari, Italy. Results from the application were useful to highlight some possible problems in the different stages of the design process. In particular, the discussed problems include a lack of crash and traffic data, difficulties with defining the road functional classifications, including rural-to-urban transitions, a lack of local inspection procedures, the recurrent problems from diagnosis, difficulties regarding the safety assessment of cycling infrastructures and sight distances, the criteria for grouping countermeasures into sets, and the choice of appropriate predictive methods. In response, appropriate solutions to the highlighted problems were presented. The usefulness of the proposed method for both practitioners and researchers was shown.

The future urban road: A systematic literature review-enhanced Q-method study with experts

“…Furthermore, some studies strongly connect this term with lower speed limits in particular urban areas, e.g. 30 km/h or even 15 km/h (Colonna et al, 2019). Gargoum et al (2016) attempted to define factors related to the urban road environment that affect the driver compliance in order to set Credible Speed Limits.…”

“…on-street parking, median islands, bus stops, pedestrian crossing) create an inconsistent road design. Design Consistency as a concept aims to define operational and geometric features that are consistent with the functionality of each road segment (Colonna et al, 2019). Mono-functionality can be considered as a necessary pre-condition to develop consistent road designs with homogenous traffic speeds (Demasi et al, 2018), as multifactional roads leads to incorrect expectations and inappropriate driving behavior (Charlton et al, 2010).…”

Improved Optimal Path Finding Algorithm of Multistorey Car Park Based on MCP Protocol

“…Unlike urban roads, the roads of car parks are often not so complicated to facilitate car owners to park [24,25]. Figure 4 shows the layout of a common car park.…”

The influence of traffic, geometric and context variables on urban crash types: A grouped random parameter multinomial logit approach

“…However, the configuration of the segments and intersections is largely different between the city centre (typically consisting of short segments with several major intersections with low spacing between them) and the rural-to-urban transition areas (typically consisting of long segments with intersections spaced with a notable distance), while neighbourhoods of the city centre are in an intermediate condition. This may significantly affect speed and driving behaviour (Silvano and Bang, 2015;Colonna et al, 2019a), with city centre areas reflecting operating speeds significantly lower than 50 km/h and transition areas reflecting operating speeds significantly higher than 50 km/h. To capture this difference, the area type variable was introduced in the analysis.…”

“…There is a considerable amount of research in the field of crash frequency modelling for urban road segments and intersections (Sayed and Rodriguez, 1999;Lord and Persaud, 2000;Persaud et al;Harwood et al, 2007). However, as highlighted in Colonna et al (2019a), most of them concern urban roads in the U.S., which may be significantly different than European urban environments. Transferability issues of models from the U.S. to European contexts (and even within the same country) were already raised indeed (Sacchi et al, 2012;Colonna et al, 2018).…”