Effective road and traffic management

Written evidence from Ken Todd (ETM 04)

Summary

The detrimental effects of congestion are widely known: the loss of time and fuel, the vehicle wear and tear, the air pollution and its ill-effects on health, the increase in the cost of doing business and the cost of goods, The cost of road accidents is also a major burden on society in terms of fatalities, injuries, health service and damage to vehicles. Less widely known is the contribution of the urban traffic control system to accidents and congestion.

Traffic regulations should forbid acts that cause danger and obstruction. Current regulations not only forbid acts which cause no danger or obstruction but encourage and command acts which do. The system runs counter to common law and common sense, to legal, engineering and safety principles, to the advice of the Highway Code, the Road Safety Good Practice Guide (RSGPG) and the aims of the Traffic Management Act. Applying sound principles to the traffic control system will eliminate its flaws at no cost.

1. Major roads The records show that traffic laws were adopted 80 years ago on the basis of personal opinion without research into their safety and operational effectiveness. The concept of giving the heavier vehicle flow on a more important road priority over the lesser flows on the side streets originated from the railway practice of main and branch lines.1 The primary purpose was, and still is for many traffic engineers, to minimise vehicle delay on the major roads. Today’s Traffic Signs Regulations and General Directives (TSRGD) requires that "no vehicle shall... enter the major road... so as to be likely to endanger the driver of or any passenger in any other vehicle or to cause that driver to change the speed or course of his vehicle in order to avoid an accident." (Underline added)

1a. Accidents at major-minor road junctions The urban major-minor road concept runs counter to basic safety principles: low speed and simple driver decisions. The most frequent and most severe type of accident at a major-minor road junction is the right-angle collision, usually blamed on the side-street driver's priority violation. Priority rules diminish the responsibilities of the major-road driver, while maximising those of everyone who wants to cross.The major road makes motorists on it go fast without looking right or left, while the side-street drivers are given a highly complex task. They have to look right and left for pedestrians when entering, and again when exiting the junction, and also for two vehicle streams, one from the right and one from the left. The right-turner has to deal with yet another traffic stream, the one from the opposite direction - seven conflicts in all, with the elderly being the most vulnerable. It was said 70 years ago that our attention gets distracted from one conflict while we concentrate on another; we should have to cope with only one conflict at a time.2 That’s why the centre refuge is the friend of the pedestrians; it lets them cross in two stages. Likewise, today’s RSGPG says driver decisions should be minimised. The danger and delay of crossing busy major roads has forced the taxpayers to pay billions for traffic lights, their manufacture, installation, operation and maintenance.

2. Accidents at traffic lights The traffic light turned out to be one of those medicines that cures one disease and gives you another. It was known by the mid-1930s that traffic lights increased accident frequency.3 They compress an hour's traffic into half an hour of green time and thereby halve all headways. They then make drivers go fast and keep close to the vehicle in front for fear of missing the green light, with their eyes up in the air rather than on the road. The combination of high speed, tailgating, diverted attention and sudden stops causes front-to-rear crashes. The Highway Code calls for moderate speed and extra care at junctions, and for safe following distance at all times. Like the major road, the traffic light encourages a disregard of the most elementary safety rules. The RSGPG says that traffic signals cause accidents to pedestrians, particularly in congested conditions, and advises their use should be avoided where possible. In London, 19% of road accidents occur at signalled junctions. An Australian study called signalised intersections the most dangerous sites on the road.4

3. Needless delay The public sees the inefficiency of the traffic control system as the needless stops and delays at a red light while no conflicting traffic is using the green. We have seen no scientific evidence of any benefits that outweigh the loss of time and fuel, the vehicle wear and tear, the air pollution and global warming. We have seen no scientific evidence showing that drivers are competent to cross or enter a major road from a minor road in the absence of conflicting traffic at an unsignalled junction but lose their competence at a junction that is signal-controlled. We have seen no scientific evidence showing that pedestrians are competent to cross a road against a red light but lose their competence when they get behind the steering wheels of their cars. The needless delay at a red light is an obstruction, an offence for which citizens get fined. To forbid licensed motorists to cross a road against red when an 8-year old schoolkid is allowed to do so is an insult to the intelligence and a sign of contempt for our civil right to use the road without getting endangered and obstructed by a system that was meant to assure safe and expeditious travel

4. Loss of capacity Less obvious to the public than the needless delay is the reduction in junction capacity and the resulting congestion caused by traffic lights.

4a. The system severely reduces capacity just when we need more of it in heavy traffic. The greater the proportion of right-turners, the lower the vehicle-carrying capacity of a junction. The right-turn problem originates from the rule that gives the through-driver from the opposite direction priority and obstructs the right-turning vehicle from leaving the junction, so that those who want to go straight ahead get blocked behind it The remedy of installing traffic lights makes the problem worse, more so when right-turn lanes and multi-phase signals are added. An official report attributed 40% of fuel consumption in US urban areas to the inefficiencies of the traffic signals.5 If the opposing traffic stream gave way to the right-turners, the problem would be gone. That’s how roundabouts work

5. The Offside Rule: In the light of the

traffic signal’s tendency to provoke

accidents, delay and congestion, we

would expect everything to be done to

employ safer, more effective and less

costly alternatives. The mini-roundabout

is such an alternative, but it is not the

only one. A junction will work without

a central island when everybody gives

way to traffic exiting the junction, as the

Automobile Association advocated 80

years ago

5a. Before the adoption of statutory priority rules in the 1920s, drivers about to enter a junction gave way ― under common law ― to those who arrived first or were already in it. A "first-come, first-served" system has been in use in the Channel Islands for more than 40 years under the name of "filter-in-turn". It is inexpensive, gives little delay, has as much capacity as a mini-roundabout, and avoids the excessive delays for the smaller roundabouts that occur when a predominant stream on the circulatory roadway prevents vehicles from entering. A "first-come, first-served" system, known as "All-way Stop" in the USA, has been called by the Federal Highway Administration the safest type of intersection control.6 Serious accidents are extremely rare.

5b. Mini- and other roundabouts are far safer than traffic signals.7 and have higher capacity,,8,9 findings confirmed worldwide. The first mini-roundabout installed on a public road in 1968 in Peterborough replaced a set of signals and raised capacity by 27%.10 Enlarging a roundabout can increase its capacity further without a need to widen the road in its entire length, as it is often done under signal control.11

5c. As there is no statutory requirement in the UK to assign priority to one road or another, junctions may operate as "unmarked" without any control whatever, just as they do when traffic signals suffer power failure.12 Attached herewith are 70 comments from commuters on the effects of traffic lights being out of action.

5d. You will be aware of the improvements in mobility and safety achieved by towns in Europe, notably Holland, Denmark, Germany and Sweden, and in a few UK locations, like Bristol. At the GLA Seminar last March, two videos showed how traffic moved fluently from all directions when the signals were turned off. Ten years of traffic management in Friesland (NL) have shown that running traffic at 30 kilometres per hour, eliminating signals and other controls in urban areas ― and leaving road users to their own devices and to their common law duty of reasonable care ― has cut accidents, delay and congestion, and saved public funds.13

6. Verdict: Today’s urban traffic control does not move traffic safely and expeditiously with minimal negative environmental impact at an economic cost. A system that causes accidents, delay and congestion is not fit for purpose. Elevated speeds, needless stops and delays, and the priority of drivers who enter a junction over those who are trying to exit have inflicted untold damage on society for the best part of a century.

7. Recommendation. I suggest that the Committee undertake a full scrutiny of the current urban traffic control system and the potential benefits of its revision.

References

1. McClintock, M. Street Traffic Control. McGraw-Hill, New York, NY, 1925, 126-127.

2. Halsey, M. Traffic Accidents and Congestion. John Wiley, New York, NY, 1941, 133.

3. Harris, G. "Modern Traffic Control." Highways and Bridges, June 19, 1934, 6-9

4. Ogden, K., et al. Factors Affecting Crashes at Signalised Intersections. Monash University

Accident Research Centre, 1994. Executive Summary.

5. National Signal Timing Optimization Project. FHWA, 1982, 1

6. Traffic Control Devices Handbook. FHWA, 2001, Chapter 10, 263.

7. Kennedy, JV, et al. Accidents at urban mini-roundabouts. TRL Report 281, 1998.

8. Blackmore, FC. "Priority at Roundabouts." Traffic Engineering & Control, June 1963, 104-106.

9. Jian-an Tan. Comparison of capacity between roundabout design and signalised junction

design. 1st Swiss Transport Research Conference, 2001.

10. Blackmore, FC. Capacity of single-level intersections. RRL LR 356, 1970.

11 Millard, R. S. "Roundabouts and Signals." Traffic Engineering & Control, May 1971,13-15.

12. The Highway Code, 176.

13. "Safer with the lights out." The Times, July 8, 2002.

January 2011