Samenvatting
Traffic congestion causes loss of time and fuel, has adverse effects on road users' behaviour and the environment and increases accidnet rates. It is therefore necessary to investigate the actual picture of the congested sections, the delay(time and duration), queue length etc. Tis has been done on two notorious sections of motorways near Amsterdam and Rotterdam. One of the conclusions is that losses caused by queues cannot be calculated from the queue length as such.