The formal phrase for tailgating is following too closely. It is a far too prevalent traffic offence and generally a sign of immaturity, impatience or carelessness.
For some vehicles, such as a motorcycle or scooter, tailgating can have fatal consequences. Indeed, for a scooter or a motorcycle to tailgate is playing with death as they can thus ill avoid a road obstacle which emerges between the tires of the car they are tailgating.
In Dangerfield v Smith, the motorcycle driver was tailgating when a lead vehicle suddenly stopped, causing a chain reaction. Caught in that chain and following too closely was a motorcycle. The driver was unable to stop and suffered "severe injuries".
Few events can be more terrifying and dangerous for a driver than having a huge truck suddenly loom up on the rear view mirror. Indeed, the mere fact of such an occurrence can, for some nervous drivers, precipitate an accident.
Almost every jurisdiction prohibits following too closely in their respective traffic statute. For example, Ontario's Highway Traffic Act:
"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.
"The driver of a commercial motor vehicle when driving on a highway at a speed exceeding 60 kilometres per hour shall not follow within 60 metres of another motor vehicle, but this shall not be construed to prevent a commercial motor vehicle overtaking and passing another motor vehicle."
The same rule is at §162 of the Motor Vehicle Act of British Columbia, and in Manitoba though the latter requires a 90-metre space between commercial vehicles. In Quebec the rule of traffic law is stated slightly differently:
"The driver of a road vehicle shall not follow another vehicle more closely than is prudent and reasonable, taking account of speed, traffic density, atmospheric conditions and the condition of the roadway."
The law is similar across Canada because it is based on common sense. We cannot see what hazards may face the driver in front of us so we should follow far enough behind to stop suddenly.
In Dangerfield, the court found the motor cycle driver responsible for his own injuries:
"Respondent (Dangerfield, the motor cycle driver) was maintaining a position too close to that car and should be further to the left of his line of travel. He was not compelled to maintain that position because of danger that drivers of cars behind him might run into him. He was driving in semi-darkness, on a wet street, in heavy traffic, under circumstances that called for more than ordinary care. He ought to know that it is not always possible for a car ahead to properly stop, and should maintain a distance behind it that would enable him to pull up with safety. If, too, he elects to drive a vehicle more than ordinarily difficult to control (it had one brake only and could not be stopped as quickly as a four-braked motor car) and he knows it, he must exercise greater care. That duty increases dependent upon the nature of the vehicle he brings into relation to others. He unnecessarily maintained a position of danger. His negligence solely explains the accident. The acts of the appellant were not a decisive or contributing cause."
But it has been a challenge in getting convictions. The courts have stymied the law and made it more dangerous on the streets for everyone by refusing to allow a conviction to stand merely because a rear-end collision occurred.
In R v Ousley, the Crown virtually challenged the court to make such a ruling failing to lead any evidence whatsoever as to the distance between the tailgater and the lead vehicle. But by the same token, if the Crown could convince the court to construe a reverse onus on the offending vehicle, prosecutions would be far simpler. The Crown was hoping that as soon as one could prove a collision occasioned by a vehicle behind, the onus would switch over to the defendant to show that the accident occurred notwithstanding his/her prudence and reasonable driving in the prevailing road conditions.
It was a double or nothing gamble the Crown lost as in the result, Canadian traffic law found itself a step behind.
There had been a collision in icy conditions: a car had hit the car in front of it as the lead car was suddenly stopping for a unanticipated road hazard.
The Ontario Court of Appeal wrote:
"The Crown asserts that in those circumstances the Crown had made out a prima facie case. We do not agree.
"His proposition would go so far as to suggest that on each occasion where a rear-end collision occurs, at some fleeting second, the following car committed (a following too closely) offence ... and that nothing more need be proved than the fact of the collision.
"In our view, the impact itself would sustain logical inferences other than that the respondent was following too closely.... The collision may have been caused, quite logically, by inattention on the part of the respondent, or by excessive speed by him."
In R v Robbins, the court went further suggesting that the offence may not be created where the lead vehicle suddenly stops. This seems to defeat the whole purpose of the offence and substantiates the famous words adopted by Supreme Court of Canada, Justice Cory in R v Hundal:
"... cases dealing with driving offences are not models of clarity. The law (in Canada) with regard to ... driving offences is a mess. As a matter of theory the law of driving offences has long been in a mess. The law has been so confused that it has almost certainly been ignored."
Nonetheless, here are the words of Justice Perry in R v Robbins:
"I think that the words follow another vehicle more closely than is reasonable and prudent import the concept of distance between two moving vehicles. It seems to me that, if the vehicle ahead suddenly stops, that creates an emergency situation which is not contemplated by the enactment.
"The essence of the offence is following too closely. The section instructs the trier of fact to determine whether the driver behind was following more closely than is reasonable and prudent, having due regard for the speed of the vehicles and the amount and nature of the traffic, and on the condition of the highway. The phrase speed of the vehicles indicates to me that the section contemplates that both vehicles are moving.
In R v Loray, the tragic consequences of tailgating were evident as was the law's expectations that "follow too closely" must always be adjusted to the weather and road conditions.
In 2001, on the Yellowhead Highway, Jaspal Singh Loray was driving a hundred thousand pound truck, with fully loaded trailer attached, and was following the passenger vehicle in front far too closely. In the trial judgment, the judge described the near-blizzard conditions as "terrible". The passenger vehicle drove slowly due to the weather; Loray did not and he likely wanted to impress upon the passenger vehicle his arrogant request that they let him by. This is a typical justification given for tailgating. The passenger vehicle tried to go a bit faster but rounding a bend in the road, it's brake lights went on and it was instantly rammed by Loray's truck. Two of the occupants in the passenger vehicle died.
Adopting words from another case, Judge Rohrmoser of the British Columbia Provincial Court wrote:
"He ought to have considered that other drivers may be less proficient than he and the resulting possible consequences of making un-signaled lane changes and tail-gating. ...
"(T)he accused in the extreme winter conditions he found himself, in order to be considered a reasonable driver, should have maintained the speed and distance appropriate to the limited visibility and the terrible road conditions that would have allowed him to avoid hitting a vehicle that loses control in front of him, going in the same direction."
- Dangerfield v Smith,  2 DLR 505 (BCCA)
- Highway Safety Code, Revised Statutes of Quebec, Chapter 24.2, §335
- Highway Traffic Act, Continuing Consolidated Statutes of Manitoba, Chapter H60, §117
- Highway Traffic Act, Revised Statutes of Ontario 1990, Chapter H.8, §158
- Hutchison, S., and others, The Law of Traffic Offences, 2nd Ed. (Toronto: Carswell, 1998), pages 204-207
- Motor Vehicle Act, Revised Statutes of British Columbia 1996, Chapter 318
- Murray, D., Manual of Motor Vehicle Law, 3d ed., Vol. 1 (Toronto: Thomson-Carswell, 2008), pages 10-86.2(2) to 10.86.3
- R v Hundal,  1 SCR 867
- R v Loray, 2002 BCPC 396. Appeal dismissed at R v Loray 2003 BCSC 806
- Re Oskey, 29 WWR 415 (BCCA, 1959)
- R v Ousley, 10 CCC (2d) 148 (ONCA, 1970)
- R v Robbins, 22 MVR (2d) 201 (BC, 1990)
Image from the Florida Department of Highway Safety and Motor Vehicles.