Reaction time for driver on horn? Also Conpiscuity Question

Q&A related to Driver Factors in Crash Reconstruction
MSI
Site Admin
Posts: 2296
Joined: Thu Jun 18, 2009 12:37 pm

Reaction time for driver on horn? Also Conpiscuity Question

Post by MSI »

Q: I have two questions for the forum:
  1. (1) Is there any data or studies on reaction time for sounding the horn (i.e. hand movement from rim of steering wheel to activation pad for the horn?
    (2) Does anyone know the ability of the human eye to detect change in angular position (rate of change of angular position), eg a slower motorcycle traveling in the same direction in front on an adjacent lane and gradually veering (acute angle 10-15 deg) towards your lane?
A: I checked with Jeffrey Muttart of Crash Safety Research and Crash Safety Solutions.

I first asked him if there was a forum on human factors?
    • IDRR is Integrated Driver Response Research (I.DRR)
      • and from their website:
          • Everything you need but speed!
            Integrated Driver Response Research (I.DRR) is a program solution for all crash reconstructionists. I.DRR allows crash reconstructionists to incorporate human factors and driver response research into real-life crash scenarios.
            I.DRR assists in determining acceleration rate, acceleration time, deceleration rate, search times, response to lead vehicles, traffic signals, steering and braking capabilities, response, avoidance, and discernability distance, among many of its calculation features.
            I.DRR utilizes a technique called "Adjustment-to-Baseline", which compares compares and applies real-life scenarios (your cases) to published, peer reviewed studies done by experts in the field.
            With I.DRR, driver response research is at your fingertips - in one place and tailored to your case! For more detailed information about the features of the program, see "More about I.DRR".
Jeff also responded as follows:
  • Q1:Is there any data or studies on reaction time for sounding the horn(i.e. hand movement from rim of steering wheel to activation pad for the horn?)
    • See Muttart JW (SAE 2005-01-0426 Factors that Influence Drivers' Response Choice Decisions in Video Recorded Crashes).
      to which he added
      • "Steering, braking and horn use PRT were the same, however, those who steer do not use the horn and vice-versa"
  • Q2:Dimension of the lead vehicle and angular rate:
    • See my other SAE paper in 2005 (2005-01-0427, Relationship Between Relative Velocity Detection and Driver Response Times in Vehicle Following Situations).

      To which he added:
      • "We tested three different sizes and did not find a difference in the shape, but did notice a difference due to relative width.
        However, we did not examine motorcycles or the dimensions of a motorcycle."