Prediction of nighttime driving visibility from laboratory data

Area of Science:

• Optics and Vision Science
• Automotive Engineering
• Human Factors

Background:

• Existing laboratory visibility data shows discrepancies when applied to real-world driving conditions with heat-absorbing glass.
• Automobile windshields utilizing heat-absorbing glass can impact driver visibility, necessitating accurate prediction methods.

Purpose of the Study:

• To reconcile the differences between calculated predictions and road test observations for driving visibility with heat-absorbing glass.
• To develop improved calculation methods for predicting visibility distance reduction caused by heat-absorbing automotive glass.

Main Methods:

• Reviewed laboratory threshold visibility data in the context of automotive driving.
• Developed new calculation models incorporating a revised visual exposure interval (e.g., 0.2 seconds) and a simulation model.
• The simulation model assumes target-to-background contrast increases as headlamp-to-target distance decreases.

Main Results:

• New calculations provide predicted visibility distance losses due to heat-absorbing glass that align well with road test observations.
• Observed visibility losses in road tests averaged approximately 3% when using heat-absorbing glass compared to regular glass.

Conclusions:

• The revised calculation methods successfully predict the impact of heat-absorbing glass on driving visibility.
• The findings suggest that heat-absorbing glass in windshields results in a modest, predictable reduction in visibility distance.