How come there is so much traffic on the roads during the day?

I live in a town of 250,000 people. OK, some people are retired, some traffic is business traffic – vans & trucks for example. But what about the rest ? Surely not everyone who is unemployed can afford a car.

Other answer:

Not everyone works 9-5, there are allot of people who work nights and late day shifts. People who are unemployed and retired do own cars.
Stay at home Mums, shift workers, Sales Reps, the retired and yes the unemployed.
traffic is largely caused by inefficient driving by drivers as well. Which is why self driving cars is such a good idea. Less accidents, less traffic, less travel time
You'd be surprised as to how many people actually do drive and own cars. I would say the majority of the traffic comes from people going to and from work. However, keep in mind that there are also still college students and high schoolers even who have to drive for summer school or simply just people running errands. 8am and 5/6 pm are usually the busiest.
You are assuming everyone that is out and about during the day is unemployed? That's a new one. Think stay-at-home parents, people with different work schedules than 9-5, people taking off work to do errands or go to personal appointments, visitors to the town on vacation; during the summer many teachers do not work and teenagers and college students do not all work summers. If no one was out and about during what you seem to consider work hours, then most businesses would have to shut down.
mark m:
They're all head to Pizza Hut for lunch.
some have night jobs. some might be mothers who don't need to work. some from other cities/towns passing through. some on vacation