Traffic experts therefore look at traffic congestion, also known as traffic jam severity. That is the length times the duration, expressed in kilometers-minutes. In the province of Utrecht, traffic jams increased by 29 percent compared to a year earlier. Nationally, the increase is slightly stronger: 34 percent. What is more telling is that traffic jams in the Netherlands are 7 percent higher this year than in the pre-corona year of 2019. This upward trend was also visible last year.