What Is The Safe Speed ?

Introduction: Numbers on a Sign vs. Real Life

The most common misconception on the road is this: "The speed limit says 90, I'm doing 85, so I'm safe." You may be legally right, but the laws of physics don't go to court.

In this series, we will move beyond viewing speed as just a legal obligation and approach it as a survival strategy. Because "Legal Speed" and "Safe Speed" are not always the same thing.

Speed: From Past to Present

The Oldest and Strangest Rule: "The Red Flag Act" (1865 - England)

Considered the world's first official speed restriction. As steam cars began to appear on the roads during that era, the public was frightened, and the Red Flag Act was enacted.

• The Rule: The speed limit was 3 km/h in the city and 6 km/h outside the city.

The World's First Speeding Ticket (1896 - England)

Offender: Walter Arnold.

Offense: Driving at exactly 13 km/h in a zone with a 3 km/h speed limit.

First Modern License Plates and Speed Limits (1901 - USA) 

With the widespread adoption of automobiles, the "man with a flag" practice was abolished.

The Era of Unrestricted Speed and Germany (1930s - 1970s)

As automotive technology advanced, between 1930 and 1970, many countries had no speed limits (especially on highways) or had very high limits. There was a perception that "Speed is civilization." The tradition of having no speed limits on Germany's famous Autobahns dates back to this period.

Present Day: "Vision Zero" and Slowing Down in Cities (1997) 

In 1997, the Swedish Parliament accepted the "Vision Zero" act, which radically changed the philosophy of traffic safety.

Philosophy: "Speed limits must be determined not by the driver's pleasure, but by the human body's tolerance to impact."

What is Safe Speed?

Safe speed is the adjustment of a vehicle's speed to suit:

• Road characteristics (curves, slopes, intersections, tunnels, residential areas),

• Weather and visibility conditions (rain, fog, night),

• Traffic density and type (pedestrians, cyclists, heavy vehicles),

• Vehicle load and technical condition,

• The driver's attention, fatigue, and experience level.

Organizations like the WHO and World Bank, which adopt the "Safe System Approach," emphasize that speed limits should be determined based on the function of the road and the vulnerability of road users; for example, 30 km/h on pedestrian-heavy urban roads, and 100–120 km/h on divided highways.

The Golden Rule: Even if the legal limit is 90 km/h, in dense fog or heavy rain, the safe speed may drop to 50 km/h or even lower.

Failure to adjust speed to conditions is the leading cause of accidents.

Source: TUIK

Reaction, Braking, and Stopping Times

A vehicle traveling at 140 km/h covers 40 meters before the driver even hits the brakes. (That is about 37% of a football field.)

Speed and Traffic Crash Risk

Speed compromises safety in two ways:

1. It increases the probability of a crash – braking distance increases, and evasive maneuvers become more difficult.
2. It increases the severity of the crash – kinetic energy increases with the square of the speed.

International Findings:

• According to the WHO, a 1% increase in average speed results in a 4% increase in the risk of fatal crashes and a 3% increase in the risk of serious injury.
• A 5% increase in average speed leads to approximately a 10% increase in all injury accidents and a 20% increase in fatal accidents.
• Various studies in Europe report a 25–40% reduction in pedestrian fatalities in cities that reduced the speed limit from 50 km/h to 30 km/h.

The impact of speed on pedestrian crashes is much more dramatic:

• In a collision at around 30 km/h, the risk of pedestrian death is approximately 10%.
• At around 50 km/h, this risk rises to over 75%.

For this reason, the 30 km/h urban speed limit is being established as the standard in many countries.

Primary Policy: Speed Management

The United Nations (UN) and the World Health Organization (WHO) address traffic safety as a global health crisis. Speed management is the central theme, particularly in the "Decade of Action for Road Safety 2021-2030" plan.

This is the UN's clearest and strongest recommendation, formalized by the 2020 Stockholm Declaration.

The Policy: In all areas where pedestrians and vehicles share the same space (school zones, markets, residential neighborhoods), the maximum speed limit must be 30 km/h.

The Rationale: A pedestrian struck by a vehicle at 30 km/h has a 90% chance of survival. However, when the speed increases to 50 km/h, this chance drops to below 20%.

Under the heading of Priority Areas:

• Combating excessive and inappropriate speed,
• Protecting vulnerable road users,
• Improving accident black spots, and Preventing loss of life through effective, continuous, and intensive enforcement.

Speed management is critically important for the effective implementation of the Safe System Approach and is a risk factor affecting shared spaces. It addresses activities related to various elements of the Safe System, such as multimodal transport and land-use planning, infrastructure, vehicle design, and road user behavior.

Appropriate speed management not only directly influences the likelihood and severity of crashes but also impacts the effectiveness of other safety interventions.

References

• 2024-2027 Highway Traffic Safety Action Plan

• General Directorate of Security – The Impact of Speed on Accidents

• World Health Organization (WHO)

• Turkish Statistical Institute (TurkStat)

• OECD Transport Research Centre – Speed Management

Gallery

Generated by AI from referenced sources.

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