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Safety Tip - Following Too Close

Following too close - can you stop safely? Recommended Following Distance:

Two (2) seconds when speeds are under 30 MPH

Four (4) seconds when speeds are greater than 30 MPH in heavy traffic

 

Average Reaction Time:  0.5 - 2.0 Seconds 

 
There is a lot that goes into stopping a car! 
  • First you have to recognize that there is a problem up ahead and figure out what to do about it, (Should I brake? Should I steer left? Should I steer right?)  That is perception time.  As decisions become more complex with more variables involved and more options available, perception time is increased. Consequently as perception time increases, more ground is covered while you are trying to figure out what to do.  The driver's age, vision, hearing, fatigue and experience also affect perception time. 
  • Next you have to get your foot onto the brake pedal. That is reaction time. It only takes a tenth of a second. 
  • Then you have to get the car to stop.  That is stopping distance. No vehicle can "stop on a dime."  How long it takes to stop depends on road conditions, the speed you are travelling, your perception/reaction time and the braking ability of your vehicle. Heavy vehicles, such as large trucks and vehicles towing trailers, cannot stop as quickly as passenger cars.  (Think about that before you pull out directly in front of one of these vehicles) 
The following time/distance chart shows the distance traveled while the driver perceives a hazard and reacts to bring the car to a stop: 
Miles
per
Hour
Feet
per
Second
Perception Reaction Distance 
Braking Distance Dry 
Braking Distance Wet 
Stopping Distance Dry 
Stopping Distance Wet 
20
29
44
19
24
63
68
30
44
66
43
55
109
121
40
59
88
76
97
164
185
50
73
110
119
152
229
262
55
81
121
144
183
265
304
60
88
132
171
218
303
350
65
95
143
201
256
344
399
70
103
154
233
297
387
451
75
110
165
268
341
433
506
This chart assumes an average PR time of 1.5 seconds and a level asphalt surface producing a drag factor of .7 for dry pavement and .55 for wet pavement.  Distances listed are measured in feet.   
 
Following Distance:
You need space to stop safely.  Follow another vehicle at a reasonable and prudent distance for the speed you are driving and for the traffic and roadway conditions.  As your speed increases, the space you leave between your car and the car ahead should increase. 

 
Two-Second Following Rule:
Watch the car ahead as it passes a certain point such as a sign, pole or tree.  Then count "one thousand one, one thousand two."  If you pass the same point before you finish the count, you are following too closely and should drop back.  This is the two second following rule.  More distance is necessary at night, in poor road or weather conditions or where visibility is limited.
 
When merging into a lane in front of another vehicle, make sure you also allow adequate distance between your vehicle and the vehicle behind you. In this way, if something ahead causes you to brake suddenly, you increase the likelihood the vehicle(s) behind you can also safely slow or stop behind you.
 
ORS 811.485 Following Too Closely; penalty.
 
  1. A person commits the offense of following too closely if the person does any of the following: 
     
    1. Drives a vehicle so as to follow another vehicle more closely than is reasonable and prudent, having due regard for the speed of the vehicles and the traffic upon, and condition of the highway. 
    2. Drives a truck, commercial bus or motor vehicle drawing another vehicle when traveling upon a roadway outside of a business or residence district or upon a freeway within the corporate limits of a city and follows another truck, commercial bus or motor vehicle drawing another vehicle without, when conditions permit, leaving sufficient space so that an overtaking vehicle may enter and occupy the space without danger.  This paragraph does not prevent a truck, commercial bus or motor vehicle drawing another vehicle from overtaking and passing a vehicle or combination of vehicles.
    3. Drives a vehicle when traveling upon a roadway outside of a business or residence district or upon a freeway within the corporate limits of a city in a caravan or motorcade whether or not towing another vehicle without operating the vehicle so as to leave sufficient space between vehicles to enable a vehicle to enter and occupy the space without danger. 
       
  2. This section does not apply in the case of a funeral procession.  Except for the funeral lead vehicle, vehicles participating in a funeral procession shall follow the preceding vehicles as closely as is reasonable and safe.
     
  3. The offense described in this section, following to closely, is a Class B violation.