Original question written by FE Exam AI Prep from the public FE Civil exam specification. Before release, a solver model re-derived the answer twice from the question alone, without its answer key, and a critic model checked the result, and the arithmetic was re-run as an executable calculation. No licensed engineer reviews these questions. It is not an NCEES question and does not come from any NCEES practice exam. FE Exam AI Prep is an independent study tool and is not affiliated with, endorsed by, or sponsored by NCEES.
Traffic Flow Rate from Vehicle Counts: FE Civil practice problem 5
For the Silver Junction arterial overlay, a resident engineer preparing a commissioning data review records 490 vehicles during a 10-min count interval. What equivalent hourly flow rate is obtained?
- A1864.2 veh/hr
- B2489.6 veh/hr
- C3176.8 veh/hr
- D2940.0 veh/hr
Show the answer and worked solution
Answer: D — 2940.0 veh/hr
Worked solution
- Step 1. Convert count interval to hours
10 min = 10/60 hr = 1/6 hr
- Step 2. Compute hourly flow
q = count/time
q = 490 / (1/6 hr) = 490 x 6 = 2940 veh/hr
Why the other choices are wrong
- Choice A
- This number sits about eighteen percent above the correct hourly rate, which does not correspond to any single well-defined computational slip in this interval conversion. Dividing the count by 1/6 hr, equivalent to multiplying by 6, yields 2940 veh/hr.
- Choice B
- This number falls short of the correct hourly rate by roughly one-fifth, which does not correspond to any single well-defined computational slip in this interval conversion. Dividing the count by 1/6 hr, equivalent to multiplying by 6, yields 2940 veh/hr.
- Choice C
- This number exceeds the correct hourly rate by close to forty-five percent, which does not match any single well-defined computational slip in this interval conversion. Dividing the count by 1/6 hr, equivalent to multiplying by 6, yields 2940 veh/hr.