Assessment of traffic safety of transport infrastructure

Introduction

The design and operation of transport infrastructure have a significant impact on road safety. The basis for optimization in terms of road safety is an objective assessment of planning, existing conditions, or traffic trials. The evaluation is carried out based on design guidelines and taking into account current research findings. In addition, insights can be derived from surveys, measurements, and observations of traffic flow or studies of the behavior of different road user groups. An example of this approach is the evaluation of the traffic trial on Rosenheimer Straße in the city of Munich. The implementation of a reduced speed limit (from 50 km/h to 30 km/h) was assessed according to various aspects.

Project Description

The City Council of Munich approved a traffic trial on Rosenheimer Straße, between Orleansstraße and Rosenheimer Platz. The aim was to make the street safer, more livable, and more user-friendly for all road users.

Overview of the key measures:

• Reduction of the speed limit from 50 km/h to 30 km/h
• Marking of the rightmost lane with bicycle pictograms
• Redesign of the intersection areas at Franziskanerstraße and Orleansstraße
• Installation of dialog displays to indicate vehicle speeds

PTV Transport Consult GmbH was commissioned to analyze the impacts of this traffic trial and to evaluate them with regard to Munich’s urban development policy goals.

The overarching objectives focused on:

• Improving residential and public space quality
• Strengthening local retail, gastronomy, and services
• Promoting pedestrian traffic and local mobility
• Encouraging mutual consideration among road users
• Ensuring the road’s capacity for motorized traffic without displacement to adjacent residential and mixed-use areas
• Maintaining and enhancing spatial compatibility of the street, particularly considering Rosenheimer Straße’s role as a district center

Special attention was also given to pedestrian requirements, such as the design of sidewalks and the quality of crossing facilities, both at and away from signalized intersections.

Project Details

As part of the evaluation of the traffic trial on Rosenheimer Straße, PTV Transport Consult GmbH conducted a wide range of investigations. The goal was to analyze the impacts of the measures comprehensively and based on factual data.

The following steps were implemented:

• Literature review on the legal framework and previous experiences with 30 km/h regulations on inner-city main roads
• Traffic counts for all road users: motorized traffic, cycling, and pedestrian traffic
• Analysis of travel times, average speeds, and queue lengths at signalized intersections (traffic light junctions)
• Recording and documentation of business displays and outdoor seating areas along the study section
• Evaluation of accident data to identify possible changes in safety
• On-site surveys of residents, business owners, and road users to assess perceptions of the changes and acceptance of the traffic trial

These measures form the basis for a well-founded assessment of the effectiveness and acceptance of the traffic trial. The results of the evaluation can be accessed via the following link.