DGT Environmental Awareness & Conservation 3 — Questions and Answers
Question 1: Which of the following road surfaces reflects the most solar heat, contributing to the urban heat island effect?
- Dark asphalt pavement (Correct answer)
- Light-colored concrete
- Permeable brick pavers
- Gravel shoulders
Correct answer: Dark asphalt pavement
Dark asphalt absorbs up to 95% of solar radiation and re-radiates it as heat, intensifying the urban heat island effect.
Question 2: What is the primary reason tire pressure directly affects vehicle fuel efficiency and environmental impact?
- Under-inflated tires increase rolling resistance, forcing the engine to burn more fuel (Correct answer)
- Over-inflated tires cause the engine to run hotter
- Low tire pressure triggers the catalytic converter to work harder
- Tire pressure affects the aerodynamic drag of the wheel wells
Correct answer: Under-inflated tires increase rolling resistance, forcing the engine to burn more fuel
Under-inflated tires flex more with each rotation, increasing rolling resistance and requiring more fuel energy to maintain speed.
Question 3: A vehicle's air conditioning system can reduce fuel efficiency by up to what approximate percentage on a hot day?
- 25% (Correct answer)
- 5%
- 50%
- 2%
Correct answer: 25%
Running air conditioning can reduce fuel economy by up to 25% in city driving by placing an additional load on the engine.
Question 4: When idling a vehicle engine for more than how many minutes is it typically more fuel-efficient to turn it off?
- 30 seconds to 1 minute (Correct answer)
- 10 minutes
- 5 minutes
- 3 minutes
Correct answer: 30 seconds to 1 minute
Modern engines consume less fuel restarting than idling for more than about 30–60 seconds, making shutoff the greener choice.
Question 5: What environmental hazard is most associated with older vehicles using leaded gasoline in countries where it was not yet phased out?
- Lead poisoning of soil and groundwater near roadways (Correct answer)
- Increased carbon monoxide in tunnels
- Accelerated ozone depletion in the stratosphere
- Higher nitrogen oxide formation in catalytic converters
Correct answer: Lead poisoning of soil and groundwater near roadways
Lead particles from leaded exhaust settle onto soil and wash into groundwater, causing toxic contamination in ecosystems and human populations.
Question 6: Which driving route choice can help a driver minimize their environmental impact when both routes reach the same destination in similar time?
- The route with fewer stop signs and traffic lights (Correct answer)
- The route using highways with higher posted speed limits
- The route with more shaded roads to keep the car cooler
- The longer route with a lower elevation change
Correct answer: The route with fewer stop signs and traffic lights
Fewer stops mean less frequent acceleration from rest, which is the most fuel-intensive driving phase, reducing total emissions.
Question 7: Carpooling is recognized as an environmentally beneficial practice primarily because it:
- Reduces the total number of vehicle trips, lowering aggregate emissions per person (Correct answer)
- Allows vehicles to use HOV lanes and avoid idling in traffic
- Qualifies commuters for federal tax deductions on fuel costs
- Reduces tire wear by distributing vehicle weight among more passengers
Correct answer: Reduces the total number of vehicle trips, lowering aggregate emissions per person
Carpooling consolidates multiple trips into one, directly reducing the total miles driven and emissions produced per commuter.
DGT Environmental Awareness & Conservation 3
Which of the following road surfaces reflects the most solar heat, contributing to the urban heat island effect?