GB2236412A - Anti-collision timer - Google Patents

Abstract

A timing device 13 provided which indicates time periods, e.g. of two seconds, indicating the expiry of these time periods with an audible and/or visible signal, so that a driver of a motor vehicle may be aided in the assessment of the time interval between the passage of a vehicle immediately ahead on the highway and that of his/her own vehicle in order to maintain a safe distance between the two vehicles. A single signal or series thereof may be provided.

Description

ANTI -COLLISION TIMER This invention relates to an nnti-collision timer "Motorway Madness" is a term familiar to all road users and applies to the phenomenon of multiple accidents, especially on motorways but equally on other trunk roads, caused basically by the tendency of drivers to travel at excessive speeds under conditions of poor visibility and/or poor grip, too close to the vehicle in front. When a vehicle is forced to brake firmly, the following vehicle (often many more than one vehicle) is unable to react and brake speedily enough to avoid colliding with the vehicle in front. Multiple collisions of up to a hundred vehicles have occurred.

The Department of Transport has tried to encourage motorists to maintain a safe minimum distance between their vehicle and the preceding vehicle under all road conditions. This distance is sometimes expressed as "vehicle lengths per m.p.h." '1yards/meters per m.p.h." Such abstract concepts have not been readily accepted by motorists. Various attempts to produce so-called head-up displays to help drivers Judge the correct headway clearance,have been made but these have usually proved too costly and none has yet been launched commercially.

An alternative method of measuring the safe minimum distance is that of expressing this distance in terms of the elapsed time between the back of the lead vehicle and the front of the following one. The Department of Transport has settled on two seconds as being the ideal, practical minimum commensurate with safety and efficient road utilization.

Some sources published by the Department suggest that twice the headway should be allowed in wet conditions, making the inter-vehicle delay four seconds on wet roads. The Department of Transport suggests that the motorist assesses the elapsed time by means of counting the seconds as "One Thousand and One, One Thousand and Two" on the basis that most people would take more or less two seconds to enunciate this phrase.

The recommended method of verbalising the count to two seconds (or four) is cumbersome, distracting, and imprecise due to the necessity of simultaneously counting, driving, and assessing Just when the vehicle in front has passed a suitable landmark. Coupled with these tasks the driver has to note exactly when his/her own vehicle passes that same landmark and note the relationship of that event to the state of the count to two seconds.

According to the present invention there is provided a timer and audible and/or visual signal which is given at a suitable interval or intervals in order that a driver may easily and accurately Judge whether his or her vehicle is travelling too closely to the vehicle immediately ahead.

An interval timer set for two seconds and perhaps adjustable to other periods such as four seconds for added safety in the wet, is set into motion by a simple means such as the press of a button conveniently located for the driver to actuate it without prejudicing the safe conduct of the vehicle. After the pre-set period has elapsed a signal which can comprise a brief tone or a flash of a light located in the drivers peripheral vision, or both, will operate. The obJect is for the driver to select a static landmark which the preceding vehicle must pass and for the driver to initiate the timer as the vehicle ahead actually passes the mark. If the signal from the timer operates before the users vehicle passes the same spot then the driver can assume that the headway between the two vehicles is within the recommended limits.If, however, the vehicle bearing the timer passes the mark chosen before the signal operates, then the distance is too small for safety.

An alternative design may comprise a timer and audio/visual signalling device as above but one not incorporating an initiation means for single shot activation but one which sets a series of timed intervals into action over a longer period of perhaps two or three minutes. The user may then not be concerned with setting the timer into motion at a precise. instant but to initiate a period of activation and note the location of the vehicle ahead with respect to a point on the road at the event of a signal from the timer, and to then note his/her own vehicles position at the next successive signal.

Care must be taken to allow for parallax errors. The method employed by the Police when using V. A. S. C. A.R (Visual Average Speed Computer And Recorder) is that of initiating the timing when the shadow of the vehicle passes over the shadow- of a roadside object or bridge, thereby eliminating parallax errors. The users instructions must be written to ensure that this concept is clearly explained.

The timer may take the form of an original equipment feature of a vehicle or that of a retro-fitted accessory.

Claims (9)

1 A vehicle borne timing device that will run for two seconds after an initiation signal is given by the user and that will cause an audible tone to sound momentarily at the expiry of that two second period in order that the user may be able to Judge the relationship of that two second period to the elapsed time between the passage of a vehicle directly ahead and the users own vehicle over a point on the highway to facilitate a safe headway between two or more vehicles travelling on the highway in the same direction.

2 A timing device as claimed in Claim 1 that incorporates an electronic timer powered by the vehicles electrical system.

3 A timing device as claimed in Claim 1 that incorporates an electronic timer that is powered by a built-in dry battery.

4 A timing device as claimed in any of the preceding Claims where a plurality of audible signals is given over a period of minutes after the device is initiated and where the interval between the audible signals is two seconds.

5 A timing device as claimed in any of the preceding Claims that has a means of switchably adjusting the dwell time that runs between the initiation signal and the audible tone or that separates adjacent tones in a plurality of tones to another value according to recommendations made from time to time-by the Government s Transport Department or other Authority.

6 A timing device as claimed in any of the preceding Claims where the audible signal has been replaced with a visual signal.

7 A timing device as claimed in Claim 1, Claim 2, Claim 3, Claim 4 or Claim 5 where the audible signal is replaced with signals of both audible and visual nature.

8 A timing device as claimed in any of the preceding Claims that is fitted as original equipment by a vehicle manufacturer.

9 A timing device as claimed in Claim 1, Claim 2, Claim 3, Claim 4, Claim 5, Claim 6, or Claim 7 that is deigned to be fitted retrospectively to a vehicle as an accessory.