WHO DETERMINES SPEED LIMITS AND HOW?

In Ohio, the process for changing the speed limit of a roadway is set forth in Ohio Revised Code article 4711.21. In most situations the authority to establish speed limits lies with the Director of the Ohio Department of Transportation (the Director).  Local governments may request the Director to change a speed limit.  For roads or streets within a municipality, the responsible local authorities are the City Council or Mayor.  For County and Township roads, the County Commissioners have authority to request a change in speed limit, and may direct the County Engineer to conduct the engineering and traffic study for the road in question. Once that study is complete, and if the study shows it “may be considered” for changing, it is forwarded on to the Department of Transportation for review and approval/denial.

The procedure for carrying out the engineering and traffic study consists of a formal calculation of the warranted speed limit. Also, some additional information is developed which may be used to support the calculated speed limit or possibly to modify it slightly. The warranted speed limit is based on five elements, which are all weighted equally. These are as follows:

  • Highway development
  • Highway features
  • Accident history
  • 85th percentile speed
  • Pace speed range

Sample warrant sheets and guidelines for conducting the engineering and traffic study are available from the Transportation Planning and Programs Administrator at each District Office of the Ohio Department of Transportation. 

Highway development is a measure of the complexity of the section of highway being studied. Private residences, businesses and factories contribute to highway development. Also, intersecting roads contribute to a high degree of highway development.  A high level of highway development contributes to a low warranted speed limit.

Highway features considered are lane width, berm quality and width, vertical curves (hills and valleys) and horizontal curves (twists & turns).

The accident history is a calculation of the number of accidents per million vehicle miles based on the most recent three-year period for which accident data is available. A record of accidents is requested from the State Highway Patrol at the State House.  The reason for each accident is closely reviewed.  Just because there is an accident does NOT mean it was caused by unsafe speed.

The remaining elements of the speed limit calculation are based on the measured speed of existing traffic. If the speed of 100 vehicles is observed and the slowest vehicle is considered #1 and the fastest vehicle number #100, then the speed of the #85 vehicle would be the 85th percentile speed.  The same list of observed speeds is used to identify the 10 mph range of observed speeds which includes the greatest number of vehicles. As an example, it might be observed that on a section of road that more vehicles drive between 37 mph and 47 mph than any other 10 mph wide range of speeds. Then the pace would be 37 to 47 mph.

In addition to the warranted speed calculation, the survey includes a few other items. Evaluators drive the section of roadway at least four times to get a feel for what seems to be a reasonable maximum speed. During a test runs, two (2) different drivers drive the section of roadway under consideration.  The driver travels at a speed they feel comfortable (without looking at the speedometer).  A device is used in the vehicle that continuously monitors even the slight changes in speed. The “speed-run” is driven in both directions with both drivers.

Topography information is also recorded along the roadway.  Typically, this includes all “substantial” items in the right-of-way, such as driveways, utility poles, fences, mailboxes, bridges, culverts, sign posts, trees and houses.

After the warranted speed limit has been calculated, the number is rounded off to the nearest five mph. For example, if the calculation yielded 48.7 mph, the warranted speed limit would be 50mph. When the engineering and traffic study is complete, the evaluator submits his finding to the Board of County Commissioners or City Council / Mayor.  The report is then forwarded to the Department of Transportation for final review and determination of new speed limit.

 

IF THERE ARE NO SIGNS POSTED, WHAT IS THE SPEED LIMIT?

Outside of municipalities, on state, county and township highways, the Ohio Revised Code states that the prima-facie (in the absence of any other evidence) speed limit is 55 mph.

 

IS THERE ANY OTHER WAY THAT SPEED LIMITS CAN BE ESTABLISHED?

Within commercial and residential subdivisions outside of municipal corporations, the Ohio Revised Code Board allows that, upon an engineering study, a Board of Township Trustees may reduce the prima-facie speed limit to no lower than 25 mph.  The Board must pass a resolution to reduce the limit and forward the information to the Director, who in turn makes the changes in the official Ohio speed limit journal.

 

WHY DO WE EVEN HAVE SPEED LIMITS?

People have been trying to solve this problem since the second set of prehistoric wheel rolled down the road.

The function of speed limits is often misunderstood by the public.  This confusion leads to typical questions that include:

What are speed limits?

What purpose do they serve?

How are speed limits set?

What do the different speed limit signs mean?

 

A uniform speed of vehicles in a traffic flow results in the safest operation.  The posted speed limits can keep the traffic flowing smoothly provided the majority of drivers find the speed limits reasonable.  To best do this, the limits must be consistent throughout the state.

The speed limits also give the motorist an idea of a reasonable speed to drive in an unfamiliar location.

The speed limits are used by law enforcement officials to identify excessive speeds and curb unreasonable behavior.

In your own neighborhood or work area, you want people to travel at a slow to moderate speed.  If you’re driving through someone else’s neighborhood or work area, you want to be able to travel quickly and smoothly.

Speed limits on our highways are established for ideal driving conditions.  During inclement weather, or when curves, hills, intersections or other potential hazards such as pedestrians and construction work zones are encountered motorist should adjust their operating speeds accordingly.  In addition, no motorist should operate a motor vehicle at a rate of speed or in such a manner as to endanger the lives of vehicle occupants or any other person.

Studies show that traffic moving at a speed that is reasonable for the road and weather conditions results in fewer accidents.  Drivers are more patient because a reasonably uniform speed allows progress with less passing, less delay, and fewer rear-end collisions.

Many people believe that lowering posted speeds will mean fewer accidents, but studies do not prove this.  Unrealistically low speeds frustrate many drivers, and potentially cause more accidents.  Some motorist may try to make up time by taking a shortcut through residential or other areas that are not suited to higher speeds and increased numbers of cars.

 

WHAT IS THE LOGIC OF SPEED ZONES?

Since most citizens can be relied upon to behave in a reasonable manner as they go about their daily activities, many of our laws reflect observations of the way reasonable people behave under most circumstances.  Traffic regulations are invariably based upon observations of the behavior of groups of travelers under various conditions.

Generally speaking, traffic laws that reflect the behavior of the majority of vehicle operators are found to be successful, while laws that arbitrarily restrict the majority of drivers encourage wholesale violations, lack public support, and usually fail to bring about desirable changes in driving behavior.  This is especially true of speed zoning.

Speed zoning is based upon several fundamental concepts deeply rooted in our American system of government and law.

  1. Driving behavior is an extension of social attitude, and the majority of drivers respond in a safe and reasonable manner as demonstrated by their consistently favorable driving records.
  2. The normally careful and competent actions of a reasonable person should be considered legal.
  3. Laws are established for the protection of the public and the regulation of unreasonable behavior on the part of individuals.
  4. Laws cannot be effectively enforced without the consent and voluntary compliance of the public majority.

Public acceptance of these concepts is normally instinctive.  However, the same public, when emotionally aroused in a specific instance, will often reject these fundamentals and rely instead on more comfortable and widely held misconceptions, such as:

  1. Speed limit signs will slow the speed of traffic.
  2. Speed limit signs will decrease the accident rate and increase safety.
  3. Raising a posted speed limit will cause an increase in the speed traffic.
  4. Any posted speed limit must be safer than an unposted speed limit, regardless of the traffic and roadway conditions prevailing.

“Before and After” studies consistently demonstrate that there are no significant changes in traffic speeds following the posting of new or revised speed limits.  Furthermore, no published research findings have established any direct relationship between posted speed limits and accident frequency, although short-term reductions have resulted from saturation enforcement efforts directed at speed and other traffic law violations.

Police agencies necessarily rely on reasonable and well recognized speed laws to control the unreasonable violator whose behavior is clearly out of line with the normal flow of traffic.

Contrary to popular belief, speed in itself is not a major cause of accidents.  In fact, there is a consensus of professional opinions that many speed-related accidents result from both excessively low and high speeds.

It is accepted within the traffic engineering profession that there is a demonstrated need to produce as much uniformity as possible in the traffic flow and to eliminate the so-called speed trap.  A speed trap may be defined as a street or road which is wide enough, straight and smooth enough, and sufficiently free of visibility limiting obstructions to permit driving a certain speed, but where the posted speed limit nevertheless calls for a much lower speed than reasonable.

 

WHAT DO REALISTIC SPEED LIMITS DO?

Realistic speed limits are of public importance for a variety of reasons:

  1. They invite public compliance by conforming to the behavior of the majority.
  2. They give a clear reminder of reasonable and prudent speeds to nonconforming violators.
  3. They offer an effective enforcement tool to law enforcement officers by clearly separating the occasional violator from the reasonable majority.
  4. They tend to minimize the public antagonism toward law enforcement officers enforcement which results from obviously unreasonable regulations.
  5. They inject an element of logic and reason onto an otherwise arbitrary and often emotional issue.

 

WHAT DO UNREALISTIC SPEED LIMITS DO?

Unrealistic speed limits are also of public importance for the following reasons:

  1. They do not invite voluntary compliance, since they do not reflect the behavior of the majority.
  2. They make the behavior of the majority unlawful.
  3. They maximize public antagonism toward the law enforcement officers, since the law enforcement officers are enforcing a “speed trap”.
  4. They create a bad image for a community in the eyes of the traveling public.

 

WHAT ARE OHIO’S SPEED LIMITS?

Section 45511.21 of the Ohio Revised Code (ORC) establishes Speed Limits and School Zones for all streets and highways within the State.  It also provides that the Director may alter Speed Limits and extend School Zones.  It further provides that local authorities may request that the Director determine and declare a reasonable and safe speed limit and extend School Zones on certain highways under their jurisdiction.

The prima-facie speed limits are given in section 4511.21 of the Ohio Revised Code-Speed limits.

In part-

  1. No person shall operate a motor vehicle, trackless trolley, or streetcar at a speed grater or less than is reasonable or proper, having due regard to the traffic, surface, and width of the street or highway and any other conditions, and no person shall drive any motor vehicle, trackless trolley, or streetcar in and upon any street or highway at a greater speed than will permit the person to bring it to a stop within the assured clear distance ahead.
  2. It is prima-facie lawful, in the absence of a lower limit declared pursuant to this section by the director of transportation or local authorities, for the operator of a motor vehicle, trackless trolley, or streetcar to operate at a speed not exceeding the following:…

 

WHAT IS SPEED ZONING?

Answer:  Speed Zoning is the process of establishing reasonable and safe speed limits for sections of roadway where the statutory speed limits do not fit the road and traffic conditions.  Speed Zones are intended to aid motorist in adjusting their speeds to those conditions.

 

WHAT FACTORS ARE CONSIDERED WHEN ESTABLISHING A SPEED LIMIT?

When performing a Speed Zone Study many traffic and road conditions are examined to determine a reasonable speed limit.  These include Highway Development (number of buildings and intersection), Roadway Features (lane widths, shoulder widths and geometric characteristics), Operating Speed (85th percentile an d10 mph pace speeds) and Accidents.

 

WHAT IS THE 85TH PERCENTILE SPEED?

This is the speed at, or below which, 85 percent of the traffic moves (85 out of 100 vehicles).

 

WHAT IS THE 10 MPH PACE SPEED?

This is the ten mile per hour range of speeds containing the greatest number of observed speeds.  Normally the pace has 60 to 70 plus percent of the observed vehicles.

Most drivers drive 5 to 10 mph over the speed limit.  Why not establish the speed limit with this in mind?

While some drivers drive faster than the speed limit, this is not true of everyone.  Experience shows that 85% of the drivers adhere to properly established speed limits which they feel are reasonable, comfortable and safe for conditions at the time.  This is what we call the 85th percentile speed.  Law enforcement officers can then target their speed enforcement efforts at the remaining 15% of drivers who are not in compliance with the speed limit.

 

ISN’T A LOWER SPEED LIMIT ALWAYS SAFER?

No, lower speed limits do not necessarily improve safety.  The more uniform the speeds of vehicles in a traffic stream, the less chance there is for conflict and crashes.  Posting speed limits lower or higher than what the majority of drivers are traveling produces two distinct groups of drivers-those attempting to observe the limit and those driving at what they feel is reasonable and prudent.  These differences in speeds may result in increased crashed due to tailgating, improper passing, reckless driving and weaving from lane to lane.  Inappropriate established speed limits also foster disregard for other speed limits, traffic signals and contribute to driver frustration.

 

WHY NOT SIMPLY POST A LOWER SPEED LIMIT AND HAVE THE LAW ENFORCEMENT OFFICERS ENFORCE IT?

Speed limits are a 24 hour a day/7 days a week/365 days a year condition.  Posting speed limits lower than the results of a Speed Zone Study does not result in voluntary motorist compliance with the posted speed limit unless there is strict, continuous and visible enforcement.  Increased enforcement is effective only at the immediate time and in the area where the law enforcement officer is present.  The availability of law enforcement officers is limited and their services must be share with other law enforcement responsibilities.  Since these lower speed limits cannot be properly enforced, they will be consistently violated and will breed disregard for speed limits in general.

 

HOW CAN SPEED ENFORCEMENT BE EFFECTIVE WHEN IT IS LIMITED TO SUCH A SMALL PORTION OF THE DRIVERS?

When the majority of drivers respect the posted speed limit, enforcement can be directed at drivers who exceed the speed limit.  When enforcement is directed at these drivers, voluntary compliance increases, resulting in a lower percentage of violators.

 

WHY NOT INSTALL 25 MPH OR 35 MPH SIGNS OR “CHILDREN PLAYING” SIGNS TO MAKE RESIDENTIAL AND RURAL AREAS SAFER?

Installing signs is only effective if a hazard is not already obvious to the reasonably safe driver.  Drivers are generally aware that they are in a residential area and do not require signs to notify them of this fact.  Additionally, improper use of these signs conveys a false sense of security to residents and does nothing to improve safety.

 

WHY NOT INSTALL STOP SIGNS, TRAFFIC SIGNALS, SPEED BUMPS, OR SOME OTHER DEVICE TO REDUCE SPEEDS?

Traffic control devices are designed and installed to solve a particular problem.  When they are misused for speed control purposes, they are ineffective and may create a hazard.  For example:

  1. Stop signs are designed to control traffic at busy intersections.  Studies show that three things happen when stop signs are installed solely to reduce speeds:
    1. Vehicle speeds are only reduced within about 150 feet of each side of the stop sign.
    2. Very few drivers actually come to a full stop for these signs.
    3. Vehicle speeds often increase between stop signs.
  2. Traffic signals are designed to control large volumes of traffic at very busy intersections or to reduce broadside crashes.  When misused, they may cause drivers to speed up to “beat the light” and may increase crashes.
  3. Speed bumps are hazardous to all vehicles especially emergency vehicles, bicyclist, motorcyclists, school buses and snowplows.

The purpose of speed bumps is to make drivers so uncomfortable going over them that they will slow down.  Tests show that the comfort level varies with the height and width of the bump and the speed of the vehicle.  Going over some bumps at higher speeds can actually make the ride smoother.  This, of course, defeats the purpose.

Traveling over speed bumps at any speed can cause major mechanical or maintenance problems to any vehicle, especially school buses and delivery trucks.  Bumps can also increase response time for fire, police and ambulances, cause accidents for bicyclists and motorcyclists, and be an attractive hazard for skate boarders.

 

WHY CAN’T WE CLOSE OUR STREET AT ONE END TO KEEP SPEED DOWN AND THROUGH TRAFFIC OFF OF OUR STREET?

Comprehensive studies must be done to define the problem and determine how a street closure will affect traffic.  Street closures affect emergency response time, snow plowing, school bus and mail routes, and residential traffic, just to mention a few. 

Traffic volumes may decrease, reducing the number of speeders.  These displaced vehicles will move to another street, relocating the problem.

 

WHY WAIT UNTIL SOMEONE IS SERIOUSLY INJURED OR KILLED BEFORE ANYTHING IS DONE ABOUT SPEEDING?

After a serious crash, speeding is often assumed to be the cause.  This may not always be true.  While crash experience is one of the factors considered in establishing speed limits, it is not the only factor.

 

WHAT CAN WE DO?

Speeding is probably the most persistent problem facing residents and law enforcement officers.  Residents observe vehicles being driven at speeds they perceive as too fast and often propose solutions that simply won’t reduce speeds or that create other traffic safety problems.

There is no single, simple solution that satisfies residents, is effective, and meets good engineering practices and standards.  Therefore, it is extremely important that residents and officials work together with a full understanding of each other’s problems, limitations, and concerns for the common goal of safety on streets and highways.