Why is this called congestion pricing as if the price would change dynamically based on traffic congestion? In fact it seems to be a static toll of $9. Or am I

Why is this called congestion pricing as if the price would change dynamically based on traffic congestion? In fact it seems to be a static toll of $9. Or am I missing something? https://en.wikipedia.org/wiki/Congestion_pricing_in_New_York_City https://en.wikipedia.org/wiki/Congestion_pricing_in_New_York...