GP in Helmond

Helmond is one of the cities in the North Brabant Deployment Site. The intersection controllers in the city of Helmond are equipped with road side units for ITS-G5 communication to provide cooperative services such as Emergency Vehicle Priority and Green Priority services.

Emergency vehicles of the city of Helmond are authorized to request the highest level of priority in emergency situations when sirens and blue emergency lights are used. Priority is granted for all signal groups on the approach of the emergency vehicle to clear the approach and conflict area ahead. This increases both the safety of the emergency vehicle and other road users, and reduces the emergency response time.

Green Priority is provided to selected logistic companies on selected routes through the city to help their heavy goods vehicles with speed advice to pass with green light more smoothly. The intersection controllers provide both the speed advice and priority to the logistic vehicles.

The on-board units (OBU) send CAM and SRM (Service Request Message) to request priority at the intersection controllers. The road-side units (RSU) at the intersection controllers send MAPEM, SPATEM and respond to SRM with SSM (Signal Status Message).

Sample Data Description

For the Emergency Vehicle Priority and Green Priority services all messages (CAM, MAPEM, SPATEM, SRM and SSM) are logged on the OBU and RSU during intersection pass events. The emergency vehicles do not have an HMI, hence the HMI logging is not available, and all intersection pass events are analysed from the messages. Logistic vehicles log all intersection pass events from their HMI in tlmevent and tlmaction file format. The speed advices for the logistic vehicles are also available from the speed profiles in the SPATEM. MAPEM messages are included only once for the intersections indicated on the map above. For a more in-depth description of the logging format and the data fields in each log type please visit Open Common Log Data Format.

Example data sets are provided over the period of November 2020 to April 2021 for both baseline and treatment events. In baseline events, an OBU does not request priority. In treatment events the OBU does request priority, but priority cannot be granted in every situation.  For emergency vehicles all events are emergency situations. Emergency vehicle events are provided on intersections 106, 504, 702, 903. For green priority for logistic vehicles events are included on intersections 103 and 806.

The following plots show an example of the logging in a Green Priority pass event. The vehicle approaches the intersection from the West. The ingress and egress approaches from the MAPEM are shown as dark green and red dashed lines on the map. The dots on the map show the vehicle trajectory from the CAM, where the colour represents the status of priority processing from the SSM. The data plot in the middle shows the time line of the event with the traffic light status (green, amber, red) from the SPATEM on the x-axis, vehicle speed from the CAM (blue line), distance to the stop line (purple line), and the remaining phase time from the SPATEM as red and green markers. The dark green line is the speed advice derived from the SPAT speed profile. The last plot shows the sequence of SRM messages (black dots) and SSM responses on the time line. The vertical axis indicate the SRM message id. As soon as priority is granted (green SSM dots), the SPAT speed advice ends and the green phase is extended until the vehicle has passed the stop line.

You can download the log data here.

Evaluation Results

Priority services are evaluated on three criteria: success rate of priority granting, safety and travel time gain.

Intersection controllers cannot provide priority in all situations. The ratio of granted versus denied priority requests is evaluated for both services. As can be expected, the ratio of granted priorities for emergency vehicles is very high (but not 100%) and much higher than for logistic vehicles.

The safety for emergency vehicles can be increased with the priority service. Approaches and conflict areas can be cleared more often than in baseline situations. Emergency vehicles are slowed down less often by other traffic, and fewer red-light crossings are observed in emergency situations. In addition, the average time to cross an intersection is reduced.

The Green Priority service for logistic vehicles is different. In this case, GP aims to help drivers to decide to pass or stop from the beginning of the approach to the intersection rather than the very last moment. The intersection controller can only help in favourable situations and does not try to give logistic vehicles a significant advantage with more frequent passes (less stops) or an overall travel time advantage compared to the baseline situation.

Following parameters are provided to relate events in the evaluation data to the log data:

Relevant indicators in the evaluation data set. The event includes the period on the ingress and egress approaches and on the conflict area: 

You can download the evaluation data here