Traffic Engineering Studies

Question 1

Measure performance for Management

and Improvement

Answer 1

Traveltimeanddelays
Speeds(spot,travel,curve)
Highwaysafety (quantification,compliance rate,driverbehavior)

Question 2

 Measure demand

Answer 2

Volume
Tripgeneration
Levelofoccupancyofparkinglots,vehicle occupancy

Question 3

Classification of traffic data

Answer 3

 Transport supply (roadway network
inventory, vehicle inventory and
characteristics)
 Transport demand (the amount of the
system used).
 Performance (how well the system
serves the demand placed upon it)

Question 4

TRAVEL TIME STUDIES

Answer 4


Alonganarterial

floating-cartechnique

Average-speedtechnique

Stationeryobserverorlicenseplatetechnique

Interviewstomotorists

Question 5

SPEED STUDIES

Answer 5

Spot Speed Methods
Radar Measurement Issues
-
Accurate value is when signal line coincides with vehicle 
 trajectory. True= measured/cosδ
-
Requires clear line of sight to give better accuracy.
-
Some vehicle maybe equipped with radar detectors.May affect driver’s desired speed
1.
Trap Length (manual&automatic)
2.
Radar(RAdio Detection And Ranging)

Question 6

Speed Parameters

Answer 6

Meanspeed:Arithmeticaverage
Modalspeed: themostfrequentlyobservedspeed
Medianspeed: speedatwhich50% islessthan
85thPercentileSpeed: Speedatwhich 85%of vehicleshavespeed equalor less
Space meanspeed