PoliceDriver.Com

The Site for Police Driver Trainers

  • Facebook
  • LinkedIn
  • Twitter
  • Home
  • Books
  • Articles
  • Tony Scotti Bio
  • Contact Us

Line of Sight and Emergency Driving

Sunday, August 17, 2014 By pdcteam Leave a Comment

line-of-sightWe have all had the experience of driving on a major highway and running into stop and go traffic, the first thought you have is that there must be an accident just over the hill or around the bend. But when you get to the top of the hill or around the bend the traffic starts to flow, and there is no accident – what caused the slowdown. Two things traffic volume and “line of sight.”

Line of Sight or Sight Distance is defined as the length of road surface a driver can see and have an acceptable reaction time. The people that are responsible for designing our highways, the American Association of State Highway and Transportation Officials (AASHTO), have guidelines concerning “line of sight”, and from those guidelines developed the all-important Decision Sight Distance (DSD)

AASHTO defines DSD as the distance needed to recognize a problem and complete the maneuver safely and efficiently. And according to the scientists who have done an enormous amount of research on driver reaction time the “average” driver needs 2.5 seconds to complete the “recognize a problem” part of the DSD.

The questions then becomes – How much distance do you use up before you get to the “maneuver safely and efficiently” part of the process. A good rule of thumb is that for every 10 MPH a driver needs 40 Feet of sight distance. If you are moving at highway speed of 60 MPH, you will need 240 Feet (40X6) of sight distance at 75 MPH you would need 300 Feet. Hence, if you are driving on the highway and for whatever reason, usually a hill, or a series of bends in the road, and there is not 240 to 300 feet of sight distance, drivers will slow down. If the volume of traffic is sufficient, it will cause an accordion affect. Please keep in mind that these distances are for the average driver

Sight distance plays an important role in police driving.  It is a major factor in determining if the event you drive into is winnable. During patrol know how far you can see NEVER DRIVE FASTER THAN YOU CAN SEE – Which means, never drive at a speed that will not give you the time to react at the given sight distance.

The question you need to ask yourself is “At the speed I am moving with the given sight distance how much time do I have – and in that time frame what can I do with the vehicle. It makes no difference what training you received and where you received it or what type of vehicle you are driving – No matter what the scenario If you don’t have enough sight distance at the speed you are moving it is a no win scenario.

Share this:

  • Click to share on Facebook (Opens in new window)
  • Click to share on LinkedIn (Opens in new window)
  • Click to share on Twitter (Opens in new window)
  • Click to share on WhatsApp (Opens in new window)
  • Click to share on Skype (Opens in new window)
  • Click to email a link to a friend (Opens in new window)
  • More
  • Click to print (Opens in new window)

Share Post

  • Facebook
  • Twitter
  • LinkedIn
  • Email
  • Print

Filed Under: Basic Vehicle Dynamics, News Tagged With: Emergency Driving, EVOC, Police Driving, Reaction Time

Connect with PDC on Social

Police Driving and EVOC on LinkedIn

Police Driving on Facebook

If you have an interest in Vehicle Dynamics and its application to driving, vehicles, and driver training, we suggest signing up for our Vehicle Dynamics Newsletter using the form below.

Leave a Reply Cancel reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

SIGN UP TO RECEIVE THE PDC EMAIL NEWSLETTER

Recent Articles

  • Emergency Maneuver vs. Cornering
  • Police Driver Newsletter – October 2021
  • Mustang Mach E Passes MSP Police Test
  • Ambush Attacks on Police Up 91%
  • The Effect of ESC on the PIT Maneuver – Plus Legal Considerations

Copyright © 2023 · PoliceDriver.Com