What is the formula for calculating flow rate (q) in vehicles per hour?

Q = n/t, where n is number of vehicles and t is time interval in hours

True or False: Time-mean speed is always greater than or equal to space-mean speed.

True. Time-mean speed equals space-mean speed only when all vehicles travel at the same speed.

Which formula represents space-mean speed calculation?
A) Arithmetic mean of speeds
B) Harmonic mean of speeds
C) Geometric mean of speeds
D) Median of speeds

B) Harmonic mean of speeds

What does density (k) measure in traffic flow?

Number of vehicles occupying a unit length of roadway at a particular instant

Fill in the blank: The fundamental equation of traffic flow is q = _____.

K × v̄ₛ (density times space-mean speed)

In the Greenshields model, at what density does maximum flow occur?

Kⱼ/2 (half the jam density)

What does a negative shockwave speed indicate?

The shockwave travels opposite to traffic flow direction (backward-forming wave)

Which LOS represents free-flow conditions with high speeds?
A) LOS C
B) LOS D
C) LOS A
D) LOS F

C) LOS A

True or False: In queuing theory, oversaturation occurs when arrival rate exceeds departure rate.

True. When λ > μ, queues grow continuously.

What is time headway in traffic flow?

Time interval between successive vehicles passing a point, measured head to head

Fill in the blank: Free-flow speed occurs at _____ density conditions.

Zero (or very low)

In Greenshields model, what speed occurs at capacity?

Vf/2 (half the free-flow speed)

What causes shockwaves in traffic streams?

Abrupt changes in traffic conditions like incidents, signals, or capacity reductions

Which LOS represents breakdown conditions with forced flow?
A) LOS D
B) LOS E
C) LOS F
D) LOS C

C) LOS F

True or False: Space headway is measured in time units.

False. Space headway (spacing) is measured in distance units like feet.

What is the relationship between flow and capacity?

Capacity is the maximum sustainable flow rate under prevailing conditions

Fill in the blank: Jam density occurs when vehicle speed equals _____.

Zero

What does PHF stand for in traffic analysis?

Peak Hour Factor

In gap acceptance theory, what is critical gap?

Minimum time interval allowing a minor street vehicle to safely complete maneuver

Which model uses exponential speed-density relationship?
A) Greenshields
B) Greenberg
C) Underwood
D) Linear

C) Underwood

True or False: Heavy vehicles reduce roadway capacity.

True. They are accounted for using passenger car equivalent (PCE) factors.

What happens to queue length when arrival rate exceeds service rate?

Queue length grows continuously over time

Fill in the blank: LOS _____ represents unstable flow at capacity.

E

What is the formula for shockwave speed calculation?

Vw = (q₂ - q₁)/(k₂ - k₁)

Which speed type uses arithmetic mean calculation?
A) Space-mean speed
B) Time-mean speed
C) Average speed
D) Flow speed

B) Time-mean speed

True or False: Capacity occurs at jam density in Greenshields model.

False. Capacity occurs at half the jam density (kⱼ/2).

What does follow-up time represent in gap acceptance?

Time between departures of successive vehicles using the same gap

Fill in the blank: In D/D/1 queuing, maximum queue length equals (λ - μ) × _____.

T (duration of bottleneck condition)

What characterizes LOS C traffic conditions?

Stable flow with noticeable restrictions to freedom of maneuver

Which factor does NOT affect free-flow speed calculation?
A) Lane width
B) Lateral clearance
C) Traffic volume
D) Interchange density

C) Traffic volume

True or False: Greenberg model is best for high-density traffic conditions.

True. It uses logarithmic relationships suitable for congested conditions.

What is the time to clear queue after bottleneck removal?

Tclear = Qmax/(μ - λ)

Fill in the blank: Passenger car equivalents account for _____ in capacity analysis.

Heavy vehicles