Identifying and assessing black spots

  • Road safety experts estimate that 50% of all crash costs occur on just about 10% of the network. But where do these crashes occur? And what causes them? PTV Visum Safety is an efficient and reliable tool for Black Spot Management. It enables you to detect, edit and analyse crash clusters. The basis for this is historic crash data collected by the police and analysed electronically. If there is no high-performance system for crash data recording in use already, PTV Vistad is a solid tool for recording high-quality crash data and is used by German police authorities to analyse crash data in eleven federal states.

    By importing this data recorded by the police, PTV Visum Safety identifies black spots visually – using heat maps and algorithms for the automatic search and generation of black spots with user-defined parameters. You can filter individual crashes according to their attributes and thus visualise and analyse them in mere seconds. The structured visualisation of noteworthy crash cluster areas, sets of meaningful symbols for individual crashes and carefully-prepared reporting variants ensure that the results are displayed plausibly for both technically-versed users and decision-makers with no traffic planning background. This forms a solid basis for an optimal decision-making process based on solid data, detailed technical insights and facts.

  • To better analyse possible causes of road crashes, the software offers a series of detailed key information stored for each crash recorded. If necessary, additional properties can be added. These include the vehicle types which were involved in the crash, the injury rate and attendant circumstances. By linking crashes to the transport model, it is possible to add further information such as number of lanes, crossings and signals as well as speed data. Country-specific features and standard features of the region can also be included in the crash data structure of the software.

  • With the Black Spot Management, the focus lies on systematically detecting crash clusters with the same features. If, for example, a high number of crashes occurs at intersections with high traffic volumes, this may indicate problems with the right of way of signalisation. If this assumption proves correct, appropriate counter measures can be planned and you can evaluate their effect on traffic in a model-based fashion.

  • Crash analyses based on a macroscopic transport models works for urban and regional settings. PTV Visum Safety can be used for cities to visually emphasise and analyse crash clusters at intersections or along corridors of urban street networks, but also supports studies in non-urban areas to focus on routes and route sections of regional networks.

Effectively manage and increase network safety

  • While Black Spot Management is a reactive approach to traffic safety, Network Safety Management is a proactive component, which is generally used for planning cycles every two to four years. PTV Visum Safety provides efficient, automatic and incremental processes for referencing crashes to the digital street network. This way, crash data can be synchronised with traffic volumes from traffic counts or ideally from a traffic model. Planners and road safety analysts assess the most critical points in the network with interactive tables and priority rankings. With the software, planners can also identify the safety potential to prioritise measures according to the severity of the crashes, classify them according to the type of road users or any other customised criteria. Traffic planners and operators of the road network can analyse the development of crash occurrences across different time periods or develop and plan possible infrastructure interventions.

  • PTV Visum Safety allows you to evaluate the safety potential and urgency of a measure in the infrastructure on the noteworthy network segments and put a number to the crash costs which can be avoided. The safety potential and calculated costs of construction or traffic-technical measures form the basis for an economic assessment, which is generally performed as a cost-benefit analysis. This is why the Network Safety Management offers all necessary information for an objective assessment of traffic safety as well as the establishment of a ranking of segments for further analysis.

  • Assessing the impact of road safety actions

    Road Safety Impact Assessment allows a risk assessment of existing and future infrastructure. Simple crash prediction models for different road types are incorporated into PTV Visum Safety. By synchronising these with traffic volumes from the transport model, traffic planners can analyse predicted crash occurrences for individual streets or entire networks and examine as well as compare various scenarios. PTV Visum Safety offers possibilities for use with an included crash prediction model (based on the relevant Swiss standard), the application of other already-defined crash prediction models or the development of custom crash prediction models. The benefits of combing transportation modelling and road safety intelligence are most evident when using accident prediction models. Strategic and operational decisions can then not only be based on the traffic flow performance, but also on their impact on traffic safety.