What are the advantages and disadvantages of toll roads for driver? Why might an individual prefer to pay a toll than to use a free road?

What are the advantages and disadvantages of toll roads for driver? Why might an individual prefer to pay a toll than to use a free road? Are there other ways to pay for highways other than tolls or higher motor fuel taxes? (Oregon is researching an alternative user fee system, you may wish to search for that information.) Are there environmental aspects to the use of toll roads versus free roads?