Traffic jam severity

  • 772 kilometre hours of traffic jams per working day

    In December 2019, the annual average of the traffic jam severity on the main roads in the Flemish Region was 772 kilometre hours per working day. This means that in the previous 12 months there was an average of 772 kilometres of traffic jams every working day for one hour.

    Traffic jam severity has continued to rise in recent years, with a peak in May 2018. In the months that followed, there was a fall in the number of kilometre hours of traffic jams.  Compared to 2012, we are now seeing well over 200 kilometre hours more.

  • Especially traffic jams in the regions of Antwerp and Brussels

    The longest and the highest number of traffic jams occur in the Antwerp and Brussels regions. In the Antwerp region, traffic jam severity rose faster than in and around Brussels. The Ghent region and the rest of Flanders are confronted with much fewer traffic jams on the main roads.


Mobility and Public Works data room: New method of calculating traffic jam severity 
Flemish Traffic Centre: Traffic indicators


Traffic jam severity: indicates the average scale of the traffic jams on a certain collection of roads. The indicator combines traffic jam length and traffic jam duration and is expressed in kilometre hours.
Kilometre hours: unit of measure used for the traffic jam severity indicator. 100 kilometre hours is the equivalent of a 100-kilometre traffic jam for 1 hour or a 200-kilometre traffic jam for half an hour.

Publication date

4 February 2020

More numbers

Previous revisions