ECIV 350 - EXAM #2 QUESTIONS & ANSWERS
List two (2) common failure types for flexible pavements - Answer -- Fatigue cracking
- Top-Down cracking
List two (2) common failure types for rigid pavements - Answer -- Transverse Cracking
- Spalling
The Present Serviceability Index (PSI) = pavement performance as it declines over time
(traffic loads & weather). When a pavement has deteriorated enough for replacement, it
is said to heave reached what point? - Answer -Terminal Serviceability Index (TSI)
In order to determine the impact on a pavement from all individual axle loads in a mixed
traffic stream, AASHTO pavement design methodology uses which equivalency factor?
- Answer -18-kip Equivalent Single Axle Load (ESAL)
If reported in veh/HR, which typically would have a higher value, the Design Hour
Volume or the design Flow Rate? - Answer -Flow Rate
Two-lane hwy w/ free-flowing traffic? (Interrupted or Uninterrupted) - Answer -
Uninterrupted flow
Urban arterial with traffic signals spaced every 1/4 mi (Interrupted or Uninterrupted) -
Answer -Interrupted flow
Interstate freeway during stop-and-go rush hour traffic (Interrupted or Uninterrupted) -
Answer -Uninterrupted flow
When evaluating a basic freeway segment, is it better to ESTIMATE the free flow speed
or to FIELD MEASURE, is the observable flow rate is 500 pc/hr/ln? - Answer -Measure
When evaluating a basic freeway segment, is it better to ESTIMATE the free flow speed
or to FIELD MEASURE, is the observable flow rate is 1200 pc/hr/ln? - Answer -
Estimate
Uninterrupted Flow - Answer -No traffic control devices
Interrupted Flow - Answer -Influenced by traffic control devices (Roundabouts,
stoplights, yield signs)
What is the measure of effectiveness for determining the quality of flow on: A Basic
freeway segment? - Answer -Density
What is the measure of effectiveness for determining the quality of flow on: A 2 lane
hwy? (Hint: 2 answers) - Answer -- % FFS
