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, Speed and Density: FE Civil practice problem 7
For the Riverview airport access road, a transportation analyst preparing a post-event engineering review uses the traffic stream relation with speed 70 mph and density 30 veh/mi. What flow rate is indicated?
- A2290 veh/hr
- B2536 veh/hr
- C2100 veh/hr
- D3025 veh/hr
Show the answer and worked solution
Answer: C — 2100 veh/hr
Worked solution
- Step 1. Use traffic flow relation
q = k v
q = 30(70) = 2100 veh/hr
Why the other choices are wrong
- Choice A
- This number falls short of the density-times-speed product by roughly one-fifth, which does not match any single well-defined computational slip in this two-term multiplication. Applying q = k * v directly on the given density and speed produces the correct 2100 veh/hr.
- Choice B
- This number exceeds the correct density-times-speed product by close to forty-five percent, which does not match any single well-defined computational slip here. Applying q = k * v directly on the given density and speed produces 2100 veh/hr.
- Choice D
- This number sits about eighteen percent above the correct density-times-speed product, which does not correspond to any single well-defined computational slip here. Applying q = k * v directly on the given density and speed gives 2100 veh/hr.