Question: A flat-fee congestion charge is a good start, since this would reduce the quantity demanded between 10 a.m. and 3 p.m., but such a fee is a blunt instrument. Making the congestion charge dynamic (or varying the price by the hour) will encourage students to move outside the window with the most popular class times in order to pay less. For instance, classes between 11 a.m. and 2 p.m. could have the highest fee. Classes between 10 and 11 a.m. and between 2 and 3 p.m. would be slightly discounted. Classes between 9 and 10 a.m. and between 3 and 4 p.m. would be cheaper still, and those earlier than 9 a.m. and after 4 p.m. would be the cheapest. By altering the price of different class times, the university would be able to offer classes at less popular times and fill them up regularly, thus efficiently using its existing resources.