How far behind the vehicle ahead? Stopping distance and the seconds rule

The Code gives no number; the SAAQ manuals do.

Short answer: the Code requires a “prudent and reasonable” distance based on speed, traffic, weather and road conditions. To measure it, you count seconds. The SAAQ driving manual recommends, on a dry road, at least 4 seconds in town and 6 seconds on a fast road, and at least 8 to 10 seconds on an icy or snow-covered road.

What the Code says

A driver following a vehicle or a bicycle must keep a prudent and reasonable distance, taking into account speed, traffic density, weather conditions and the state of the road (Code de la sécurité routière, Quebec’s Highway Safety Code, s. 335). The SAAQ handbook spells out the goal: enough space to stop without a collision if an emergency forces you to brake (Guide de la route, ch. 4, “La distance entre les véhicules”).

On a road where the limit is 70 km/h or more, vehicles travelling in a convoy must also leave enough space between them for a passing vehicle to move in safely (s. 336).

How many seconds?

The Guide de la route mentions the “two-second” rule as a way to judge the distance. The SAAQ manual Conduire un véhicule de promenade (2022) gives more cautious intervals, which are minimums:

Conditions	Recommended interval
In town, dry road	4 seconds or more
Fast road, dry	6 seconds or more
Icy or snow-covered road	At least 8 to 10 seconds
Stopped behind a vehicle	One vehicle length (about 5 m): you should see its tires and the road

Source: Conduire un véhicule de promenade, ch. 4, “Garder ses distances à l’avant” and “La distance sécuritaire à conserver à l’arrêt”.

How to count: pick a fixed landmark (a pole, a shadow). When the vehicle ahead reaches it, count “one thousand and one, one thousand and two…” until your vehicle reaches it. If you get there before the count is done, slow down. In rain, at night, in fog, on gravel or with worn tires, increase the interval.

Stopping distance

Stopping distance is the minimum space needed to bring the vehicle to a stop. It adds up three parts (Conduire un véhicule de promenade, ch. 4, “La distance d’arrêt”):

Stage	What makes it longer
Perception time: seeing the hazard	Health, quality of vision
Reaction time: getting your foot on the brake	Reflexes, stress, fatigue, state of mind
Braking distance: from braking to a stop	Mechanical condition of the vehicle, road and weather conditions

It also depends on the vehicle’s mass and speed: the faster you go, the longer it gets, and an icy road greatly reduces tire grip.

If someone is tailgating you

The manual advises leaving even more space ahead of you, which may encourage the other driver to pass. If they keep it up, leave the road as soon as you can do so safely (ch. 4, “Garder ses distances à l’arrière”). Don’t brake hard without need: that is an offence (s. 436, 2 points).

Demerit points

Following too closely (s. 335): 2 points and a fine of $200 to $300 (Regulation respecting demerit points, schedule, item 9; s. 510).
Driving too fast for conditions (s. 330): 2 points (schedule, item 8).

Key points for the test

The Code: a “prudent and reasonable” distance.
SAAQ manuals: measure it in seconds; 4 s in town, 6 s on fast roads, 8 to 10 s on ice or snow.
Stopping distance = perception + reaction + braking.
Following too closely: 2 points.

Test yourself on this topic
Original questions with explanations and sources, “Driving techniques” section.
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Official sources

Code de la sécurité routière (Highway Safety Code, CQLR c. C-24.2), ss. 330, 335, 336, 436 and 510
Règlement sur les points d’inaptitude (Regulation respecting demerit points, CQLR c. C-24.2, r. 37), schedule, items 8, 9 and 26
SAAQ, Guide de la route (4th ed., 2024, French), ch. 4, “La distance entre les véhicules”
SAAQ, Conduire un véhicule de promenade (2022 ed., French), ch. 4, “Maintenir une vitesse et une distance sécuritaires”, “Garder ses distances à l’avant”, “Garder ses distances à l’arrière”, “La distance d’arrêt”, “La distance sécuritaire à conserver à l’arrêt”

General information page, current as of 2026-10-28. If in doubt, the official text prevails. Rules can change: check saaq.gouv.qc.ca and legisquebec.gouv.qc.ca.