this post was submitted on 29 Aug 2023
173 points (92.6% liked)
Cars - For Car Enthusiasts
3927 readers
29 users here now
About Community
c/Cars is the largest automotive enthusiast community on Lemmy and the fediverse. We're your central hub for vehicle-related discussion, industry news, reviews, projects, DIY guides, advice, stories, and more.
Rules
- Stay respectful to the community, hold civil discussions, even when others hold opinions that may differ from yours.
- This is not an NSFW community, and any such content will not be tolerated.
- Policy, not politics! Policy discussions revolve around the concept; political discussions revolve around the individual, party, association, etc. We only allow POLICY discussions and political discussions should go to c/politics.
- Must be related to cars, anything that does not have connection to cars will be considered spam/irrelevant and is subject to removal.
founded 1 year ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
It's not car lengths, it's seconds. You need roughly 2 seconds between you and the person in front of you. That gives you time to react and emergency brake if needed. At 70mph, 2 seconds is a little over 200 feet, not 3 car lengths. Average reaction time is about .75 seconds; you see something, and you start reacting to that thing--not you finish reacting--in .75 seconds. At 70mph, you will travel 75 feet before you can even realize that you need to get your foot off the gas and hit the brakes.
2 sec is not practical in daily driving in busy city. It is correct if there is some car stopped there then you need completely stop. People take the risk and follow closer because usually everyone brake so give you more time/distance.
But if there's a road hazard hidden by the vehicle in front of you, or a person/animal steps out onto the road, if something falls off the vehicle ahead of you (note that I have had an entire wheel go through my windshield when it fell off the car ahead of me; good times), then you just aren't going to have enough tie to do anything.