Extension : Extension 1.1: Speed Limit Fine Calculator


You will calculate the fine one would have to pay for going over the speed limit in the state of Massachusetts according to the Massachusetts DMV.

By completing this work, you demonstrate that you can:

  • Create a Java class on your own
  • Arrange for the class to take inputs of interest
  • Compute output values of interest
  • Produce meaningful output based on your computations

Have you ever received a ticket for speeding? If so, how do you feel about it? Were you going more or less than 10 miles over the speed limit?

The objective of this extension is to allow you to practice assignment statements and data types as well as for you to create a practical tool, though of course we hope you never need to compute a speeding fine for yourself.

Consider the following story:

  • Pat is driving a Mini Cooper at 85 MPH on a road that has the speed limit of 60 MPH.
  • Pat is therefore going 25 MPH over the speed limit.
  • If Pat is caught speeding, what would be Pat’s fine?

    We’ll model the fine after Massachusetts law:

    • A fine is assessed only if the driver’s speed is over the speed limit.
    • For the first 10 MPH over the speed limit, the fine includes both a $50 base fine and a $50 surcharge.
    • If the driver is more than 10 MPH over the limit the fee increases. For each additional MPH past the first ten and additional $10 it added to the fine.
    • Thus, Pat owes $100 for going at least 10 MPH over the speed limit (50 base fine+50 surcharge = 100). To this, we add $10 for each additional MPH. Pat was going 15MPH above the 70MPH that triggered the ticket. Consequently, we add $10 * 15 = $150 for the additional 15 MPH. Thus, Pat owes $250.


  1. First, create a SpeedLimit Java class in the speeding package of the extensions source folder.
  2. Consider and decide upon the data type to represent information of interest to this problem.
  3. You must ask the user for some input values. If you do not recall how to use ArgsProcessor, review the video entitled Prompting the user for input values.
  4. Arrange for your program to produce output such that:
    • For the first 10 miles over the speed limit, the fine is 100 no matter what
    • For any additional mile past the first ten, 10 dollars are added to the fine

    Beware: Make sure your program works correctly for 0 MPH and all possible positive speeds.

  5. Finally, your program should print how many miles you were going over the speed limit and how much money the fine will be.

Sample output based on the example story above:

You reported a speed of 85 MPH for a speed limit of 60 MPH.
You went 25 MPH over the speed limit.
Your fine is $250.

You must compute the required information without using if-statements. To evaluate an expression conditionally, use the ternary operator, an example of which follows:

int x = (y > 7) ? 12 : 5;`

The variable x is set to 12 if y’s value is greater than 7; otherwise x is set to 5.