OHTA.ca

I didn't want to put two cents on another thread. I do have over 400hrs of speciality training in collisions. I know we see this all the time and to me it is just baffling.

Why are people following too close on the highways and city streets?

It takes an average of 1.5 seconds for someone to see a danger ahead and process that in their mind and tell their foot to step on the brake. It then takes about 1.5 seconds for foot pedal, to either mechanically or electronically advise the computer in the car to actuate the brakes, the hydraulics then push the fluid, then brake pads then grab the rotors, tire stop rotating and friction between tire and surface slows the car.

Now that is 3 seconds.

So how far will your vehicle travel in those 3 seconds ?

An car is typically 5 to 6 metres in length.

50km/hr = 13.8 metres per sec = 41 metres

60km/hr = 16.6 metres per sec = 50 metres

70km/hr = 19.4 metres per sec = 58 metres

80km/hr = 22.2 metres per sec = 66 metres

90km/hr = 25.0 metres per sec = 75 metres

100km/hr = 27.7 metres per sec = 83 metres

Of course there is other variables that factor into the equation such as coefficient of friction (frictions value between the tires and whatever type of road surface)

Braking efficiencies which is how well the brakes are maintained.

158. (1) The driver of a motor vehicle or street car shall not follow another vehicle or street car more closely than is reasonable and prudent having due regard for the speed of the vehicle and the traffic on and the conditions of the highway.

Definitions:

Reasonable- fair and sensible

Prudent - showing care and for the future

So was all food for thought, ensure you are being sensible, keep predicting that vehicle in front could have to stop suddenly for a child that runs out, moose that comes onto the highway or other obstacles.....in the big picture what really is 1/2 a football field up the road going to do, other than possibly put you in a dangerous position.

Leave lots of room and don't follow too close.

Ps... I always wonder why people are so close even in a drive thru? I certainly don't want to be inhaling toxic fumes as the exhaust pumps out into the front of my car

With an average car length of ~5m. If you were to leave 83m of distance to the vehicle in front at freeway speeds; expect to be tailgated (irony) and giving an open invitation to allow multiple vehicles to slot into your 83m braking distance buffer.

I do agree paying lip-service to the vehicle in front, will not do anyone any favours. However, leaving the door open to have cars slot in front... is equally just as unsettling; especially, if they start applying their brakes in order to negotiate the lane change in front of you.

Ultimately, we all need to have situational awareness and look as far ahead as possible and anticipate what other vehicles and drivers are going to do. No matter how we operate our motor-vehicles there are going to be freak events through act-of-god which are unavoidable: https://youtu.be/gmF9oBK8x2s

Also keep in mind that motorcycles and performance vehicles can stop 100-0kph in 30-35m.

iFly55 wrote:

Also keep in mind that motorcycles and performance vehicles can stop 100-0kph in 30-35m.

I don't understand what your getting at here? As my post above was a reference of distance travelled and coming to a complete stop with various speeds once a danger was detected.

This is a ticket that I would love to see handed out a lot more often.

ynotp wrote:This is a ticket that I would love to see handed out a lot more often.

I second that notion... I too hate it when people are following too close and I wonder what is going on their head?

When it is rush hour traffic and you are simply following the flow of traffic, by some one riding your rear bumper, it's not like you are/can go any faster, so what does this action accomplish? Other than put your and possibly his/her life in danger?

More so when it's an 18 wheel truck, following a 4-wheeler with less than one car length gap, he can't even see his break lights.

Professional truck drivers do not do this, you can see them leaving huge gaps between themselves and cars ahead, it's the young truck driver wana bees that do this and have no idea how dangerous it is. On 409 I used to see this tandem dump truck that used to drive as if he was driving a Porsche, using the merging lane as a passing lane just to cut in front of 5-7 cars.

Good post, thank you

@hwybear, oops i completely misread those numbers; i thought it was in reference to stopping distance, but rather it's the "reaction" distance.

I was taught 1 car length for every 10 miles ph

or per 16kph

about the same so I agree.

Cheers

Cindan

To be honest, I don't think that formula is very good...

You need to take into account many variables, road condition, your tires, your vehicle stopping power, your own response time, other cars around you, open space to steer away to avoid a collision and who knows what else that I can't think of.

There was a pilot program MTO tried in Oshawa back in early 90s when they had chevrons painted along 401 and signs stated to keep two chevrons apart.

If my memory serves me right, keeping that distance would mean keeping 100-150 meters back at 100 kmh speed.

There's a stretch of motorway in the UK with this,

it bloody well works a treat, no bunching up. no traffic, after you've gone through this a few miles,

drivers start acting like dickheads

Observer135 wrote:To be honest, I don't think that formula is very good...

You need to take into account many variables, road condition, your tires, your vehicle stopping power, your own response time, other cars around you, open space to steer away to avoid a collision and who knows what else that I can't think of.

There was a pilot program MTO tried in Oshawa back in early 90s when they had chevrons painted along 401 and signs stated to keep two chevrons apart.

If my memory serves me right, keeping that distance would mean keeping 100-150 meters back at 100 kmh speed.

I agree 100%. I always leave tons of room but people take this as an invitation to cut me off so I am constantly having to adjust. I also drive at the speed limit so quite often I am getting tailgated.

This charge seems like it would be very hard to prove unless a collision is involved which is why we probably don't see many of these tickets. Government (and therefore police) are really only concerned with taxation so we see easy tickets like speeding, licence plate stickers, and insurance slips. Every time I am on the 401 I see numerous instances of people following too closely, passing on the right, failing to move to the right, etc, but all I ever see the OPP doing is speed traps.

I wonder if this would be a good opportunity for car manufacturers - using a range finder it shouldn't be too difficult to calculate an approximate safe reaction/stopping distance and alert the driver.

Speaking of drive thrus... I don't use them very often but maybe I will start leaving a bit more space there too. Although I hate those ones with two ordering lanes that merge; I feel like they just create unnecessary tension.

Observer135 wrote:To be honest, I don't think that formula is very good...

You need to take into account many variables, road condition, your tires, your vehicle stopping power, your own response time, other cars around you, open space to steer away to avoid a collision and who knows what else that I can't think of.

There was a pilot program MTO tried in Oshawa back in early 90s when they had chevrons painted along 401 and signs stated to keep two chevrons apart.

If my memory serves me right, keeping that distance would mean keeping 100-150 meters back at 100 kmh speed.

The above is plain and simple chart for minimal stopping distances at certain speeds. Based solely on human reaction time (1.5 seconds) and mechanical time (vehicle components).

It does not factor in other items that affect a vehicle stopping which extend the above distances, such as: type of surface, surface viscosity, grade, super elevation, braking percentage per type of vehicle, how many brakes were working on that vehicle, vehicle mass, etc..

hwybear wrote:I didn't want to put two cents on another thread. I do have over 400hrs of speciality training in collisions. I know we see this all the time and to me it is just baffling.

Why are people following too close on the highways and city streets?

Ps... I always wonder why people are so close even in a drive thru? I certainly don't want to be inhaling toxic fumes as the exhaust pumps out into the front of my car

Because .... most cars have average braking power and it is a little rare for people to apply maximum braking force ... people get lured into a false sense of safety, primarily because they have never or rarely experience maximum braking force from a car in front of them.

So sadly, I would expect, the answer to your question is simply, they just don't know any better.

I switch the air flow to recirc when in drive thrus for an extended period.

I think all drivers should be required to take an enhanced driving course, with focus on braking and skid control. I learned so much from autox school and club days at Mosport - you quickly realize the distance it takes to scrub speed for a tight corner at 130-140km/h (and that was with a car with 13" rotors, 4-piston Brembo calipers, and 245/40 tires).

I've never understood why people tailgate, especially those drivers that hug your bumper and continually "peek" around you like they expect you to go somewhere in rush hour traffic. Argh...