1 / 12

The safety problem: nature of the problem, extent (partially covered already), factors

The safety problem: nature of the problem, extent (partially covered already), factors. CE 552 week 4. Hauer Philosophy. You can learn the effect of a safety treatment with before and after observation – wrong You have to have true randomized experiments to learn anything – wrong

quiana
Download Presentation

The safety problem: nature of the problem, extent (partially covered already), factors

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The safety problem: nature of the problem, extent (partially covered already), factors CE 552 week 4

  2. Hauer Philosophy • You can learn the effect of a safety treatment with before and after observation – wrong • You have to have true randomized experiments to learn anything – wrong • You can learn from experience – ok • You must take great care in doing so – ok • You shouldn’t experiment – wrong • “the only way to find out what will happen when a complex system is disturbed is to disturb the system, not merely to observe it passively” – Box 1966

  3. Hauer Philosophy • Opportunities abound • If we do evaluate, we do so “in-house” because there is risk of failure • We do not publish because the measure failed • What is needed … • Sound methodologies • Collective will to employ them properly

  4. Hauer quotes • “Perhaps we transportation engineers can not act in good faith as the custodian of traffic safety because the goal of safety and efficiency are too often in conflict” • “Within limits, highway traffic engineers can make roads safer or less safe so we must know the safety repercussions of our choices”

  5. Road Safety Defined (From a Science-based Perspective) • Improved “security” may decrease “safety” • Accident or crash? • Is safety the number of crashes per time? What if some days have no crashes – perfectly safe? • Use running average? • Use longer period of time? • Safety may change – must be allowed to • Requires use of statistics (expected values) and reliability during a specific period • Counts are a “hint” at the underlying numbers

  6. Federal Transportation Goals • Safety • Old: reduce fatality rate to 1.0 • New: ??? • Congestion • Preservation • Environment

  7. Evans’ thoughts • “Factors” rather than “cause” (contributing circumstances) • Is it safer to keep a pet crocodile than a pet dog? – how to answer this?

  8. Human Factors • Driver intelligence/skill • ladder in car • Des Moines drivers • Reaction time tests http://www.bbc.co.uk/science/humanbody/sleep/sheep/reaction_version5.swf • Distractions • docs\text_messaging_crash.mht • Distracting Miss Daisy (includes risk compensation) • Cell phone bill; KCCI report • Speeding • Why the EZ pass speed is 15 mph • Fricker p. 307 “think about it”

  9. NCHRP 500 • aggressive driving http://onlinepubs.trb.org/Onlinepubs/nchrp/nchrp_rpt_500v1.pdf • unlicensed drivers http://onlinepubs.trb.org/Onlinepubs/nchrp/nchrp_rpt_500v2.pdf • seat belts http://onlinepubs.trb.org/Onlinepubs/nchrp/nchrp_rpt_500v11.pdf • Drowsy/distracted http://onlinepubs.trb.org/Onlinepubs/nchrp/nchrp_rpt_500v14.pdf • Alcohol http://onlinepubs.trb.org/Onlinepubs/nchrp/nchrp_rpt_500v16.pdf

  10. Road Crash Factors • http://www.collegehumor.com/video:1754304

More Related