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Human Factors

Visibility and conspicuity

Our experts determine whether something important was visible and conspicuous.

A road ahead seen through a windshield toward a low sun

Nighttime visibility analysis is one of the firm’s deepest specialties and the subject of much of our published research: camera calibration for luminance estimation, quantifying retroreflective materials from digital imagery, equivalent-contrast depiction of night scenes, and the validation of physically-based render engines against photometric ground truth.

The same analysis supports driver performance and premise liability work.

Scope

What this covers

Roadway subjects

  • Stopped or disabled vehicles
  • Pedestrians, cyclists, and motorcycles
  • Construction equipment and work zones
  • Roadway furniture and delineation
  • Retroreflective materials and reflectors

Premise subjects

  • Stairs and stairways
  • Parking stops and wheel stops
  • Walkways and vertical discontinuities in sidewalks
  • Platforms and uncovered holes

Measurement

  • Scene luminance mapping from calibrated imagery
  • Target and background contrast
  • Illuminance and lighting system performance
  • Coefficient of retroreflection by entrance and observation angle

Gallery

Video

Forensically Accurate Digital Media
Tanker trailer on shoulder
Tanker trailer with DOT emergency triangles

Peer-reviewed research

Published work behind this practice area

Authored by our experts and peer-reviewed by external experts.

All publications

Who does this work

Experts on this practice area

Justin Ngo

PE, ACTAR

Accident reconstruction, human factors, and vehicle testing

  • Heavy truck and passenger vehicle reconstruction
  • Human factors: perception, attention, and response
  • Premise slip, trip, and fall analysis
  • Vehicle testing, instrumentation, and data analysis

4 publications

Jeffrey Suway

PE, ACTAR

Visibility and conspicuity, human factors, and accident reconstruction

  • Night visibility and conspicuity
  • Lighting issues
  • Human factors
  • Accident reconstruction

27 publications

Request a case review

Send us the incident location, the date, and what is in dispute. We'll discuss what analysis is possible with the evidence that exists, and what it would take to get.