While Visions of Roadrunners Danced in His Head
Dr. Sarah's Report (Solutions)

                                                                                                                        Dr. Sarah J Greenwald
                                                                                                                        August 29, 2002

Wile E. Coyote
Philadelphia City and County Prisons
8201 State Road
Philadelphia, PA 19136

Dear Wile E. Coyote:

I just received your letter and I am very sorry to hear of your predicament. Upon reading and reviewing your case, I have decided that I will be able to offer you advice. Using the information that you have given me, I have analyzed the mathematics related to your incarceration and I have prepared a report in order answer your questions and help you argue your case in front of the judge.

The Events Leading to Your Arrest

You were stopped at a rest stop on 95 South when you saw the Roadrunner run past you at a speed of 120 miles/hour, as clocked by the automated speed checker. After waiting a few moments and then speeding instantaneously, you used your velocitometer to measure the percentage that you were traveling relative to him. The velocitometer reported that you were traveling at 60% of the Roadrunner's speed. You then maintained this speed until your arrest on charges of excessive speeding, reckless driving and being a public menace.

Speeding Charges

The first concern is whether or not you were speeding. We will calculate how fast you were traveling. Since your device read 60%, this means that you were moving at 60% of the Roadrunner's rate of travel. Since the Roadrunner was traveling 120 miles/hour, then you must have been traveling 60% of 120 miles/hour.

In order to calculate your speed, we must calculate 60% of 120 miles/hour since your speed is equal to the Roadrunner's speed times the percentage that you were traveling relative to him. We must first convert 60% to a decimal. Notice that 60% means 60/100. Hence, by moving the decimal place over to the left 2 places, we see that 60% equals .60 . Now we can multiply .60 times 120, which equals your speed of 72 miles/hour.

Now that we know that you were traveling at a speed of 72 miles/hour, we can determine whether you were speeding excessively. You neglected to mention what the speed limit was on 95 South. Even though I can see that you were placed in jail in Philadelphia, this is still not enough information in order to determine the precise speed limit. Without this piece of information, it is impossible for me to accurately determine if you were breaking the speed limit, but I can offer my opinion. On most interstates in the northeast, the speed limit is between 50 and 75 miles per hour, with the most common speed limit ranging between 60 and 70 miles per hour. If this was the case, then you definitely were speeding, but you were not speeding excessively. Excessive speeding charges are usually defined as traveling at least 15 miles an hour over the posted speed limit. If the posted speed limit was above 60 miles per hour than you were not speeding excessively and you should plead innocent to this charge. But, if the posted speed limit was below, then you should plead guilty.

Reckless Driving and Public Menace Charges

We will now address the reckless driving and public menace charges.

For the reckless diving charge, I recommend that you plead innocent on the basis of the fact that you were running instead of driving. Even if the judge does not accept this distinction, if you can argue that you put no one in danger, then you can plead innocent. On the other hand, if you were weaving in and out of traffic and placing other drivers in danger, you must plead guilty.

For the public menace charge, I recommend that you plead guilty because I believe that trying to eat someone constitutes public menace behavior. You might plead innocent to this charge by special reason of insanity. After all, you were only following your natural instinct and you can argue that this is an uncontrollable urge.

Catching the Roadrunner

I know that your goal was to catch the Roadrunner. I will explain to you how you can use your velocitometer in order to do so by using common sense instead of mathematical calculation.

You were traveling less than 100% of the Roadrunner's speed. This means that you were traveling more slowly than him. Hence, even if the police had not stopped you, you would never have caught up with him with this velocitometer reading, as he would have continued to leave you behind by increasing the distance between the two of you.

If you had traveled at a speed so that the velocitometer read 100%, this would mean that you would have been traveling at the same speed as the Roadrunner. When you began the chase, you hesitated a bit before running after him. Hence, you started off behind the Roadrunner, and so you could not have caught up to him by traveling at exactly his speed. Instead, you would have stayed exactly the same distance behind him.

In order for you to catch the Roadrunner, your velocitometer would have had to read anything over 100%. A reading over 100% would mean that you would have been traveling faster than him and would have shortened the distance between you until you caught up to him. Even a reading of 100.00000001% would have resulted in your success and a tasty dinner, because eventually you would have caught up to him. The greater the percentage reading over 100%, the faster you could have caught up to him, but any reading over 100% would have worked.


Now that you understand the mathematics relating to your charges, I hope that your trial goes smoothly. I encourage you to plead innocent to the excessive speeding charge based on my arguments. As for the other charges, you will have to decide what you want to do. Good luck with the trial.


Dr. Sarah