How can traffic data be used to design safer roundabouts?

In the context of intersection design, especially in order to assess the merit of a roundabout, it is key to possess sufficient time series so as to figure out peaks and other special features. Sites exhibiting seasonality render such requirement more profound. The last few years pose an additional challenge in this respect, due to prolonged pandemic effect in traffic patterns. Beyond counts / turning movements, Road Safety data is also critical in terms of incorporating specific design elements for vulnerable users (PTWs, bicycles, pedestrians), also depending on typical weather conditions and participation of Heavy Vehicles in traffic composition. There are excellent examples applied in Netherlands and other countries with high capacity

To improve the roundabout productivity, the proper device shall be selected for the traffic count duty. Traffis data analysis shall be carried out. We need to see the most traffic direction that effects the equation for the roundabout. The solution is divided into alternatives. Alternative choices are assigned based on. 1- cost-effectiveness 2- quality of solving the black spot 3- using a simulation program to make sure the objective is achieved, and help for decision-making.

In addition, the interpretation of data and consideration of potential issues, varies depending on the location of an existing or envisaged roundabout. Being located along very busy arterials of high AADT obviously means lower tolerance for queue length and bottleneck triggering point (as backwards propagating wave). Even more, this is the case for close intersections/roundabouts (or, even worse, when combined to extra traffic signal close by due to a special facility such as hospital or other trip attraction pole)

Additionally, users' feedback is an essential source of monitoring and optimization. That's why their planning and collection strategy must be done in advance. It's not always enough to ask users for feedback but rather to implement regular and functional interactivity, which is often more effective for feedback collection.

Analyzing traffic data can help design safer roundabouts by identifying patterns, such as peak traffic times and potential congestion points. This data aids in optimizing roundabout geometry, determining appropriate entry and exit lanes, and establishing efficient traffic flow. Additionally, studying accident data enables designers to address specific safety concerns, leading to improvements like better signage, visibility, and pedestrian facilities.

For the context of Kampala, Uganda . Congestion is big hindrance especially when it comes to peak days/times. Traffic data helps in visualizating such information hence it being used to set up round shouts to cub such incidences like congestion among others