ACTAR Visibility & Lighting Conditions

Question 1

In traffic accident reconstruction, 'overdriving headlights' occurs when:

Accepted Answer

A driver travels at a speed where stopping distance exceeds headlight illumination distance

Answer

A driver uses high beams in fog, creating backscatter that reduces visibility

Answer

Headlights illuminate beyond the legally permitted maximum distance

Answer

A vehicle's headlights are misaligned, causing glare for oncoming drivers

Question 2

What is the standard low-beam headlight illumination distance commonly used in nighttime accident reconstruction analyses?

Accepted Answer

150–160 feet

Answer

50 feet

Answer

100 feet

Answer

300 feet

Question 3

Which unit is used to measure the retroreflectivity of pavement markings in traffic engineering and accident reconstruction?

Accepted Answer

Millicandela per square meter per lux (mcd/m²/lux)

Answer

Foot-candles (fc)

Answer

Lumens per square foot (lm/ft²)

Answer

Candela per lumen (cd/lm)

Question 4

The term 'conspicuity' in accident reconstruction refers to:

Accepted Answer

The ease with which an object can be detected and recognized by a driver

Answer

The legal definition of a road obstruction under state traffic codes

Answer

The brightness of headlights measured in lumens at the lamp

Answer

The angle of incidence of headlight beams on a reflective surface

Question 5

In nighttime accident reconstruction, the 'available sight distance' is primarily limited by:

Accepted Answer

The illumination distance of the vehicle's headlights

Answer

The posted speed limit on the roadway

Answer

The coefficient of friction of the road surface

Answer

The ambient air temperature at the scene

Question 6

What atmospheric condition is most likely to cause 'disability glare' for drivers at night?

Accepted Answer

Oncoming vehicle headlights directed toward the driver

Answer

High relative humidity with no precipitation

Answer

Dense fog reducing visibility to under 100 feet

Answer

Bright moonlight reflecting off a wet road surface

Question 7

When reconstructing a nighttime collision involving a pedestrian wearing dark clothing, which factor is MOST critical in determining the driver's available reaction distance?

Accepted Answer

The detection distance of the pedestrian under prevailing headlight illumination

Answer

The pedestrian's walking speed and gait pattern

Answer

The posted speed limit in the collision area

Answer

The road surface color and albedo