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Original Author: Hemsley, Sid
Date of Material: 05/30/2001

Public health and safety
Streets--Planning and engineering
Streets--Signs and signals
Traffic--Laws and regulations

Speed Bumps

Reviewed Date: 05/11/2020
MTAS was asked for information on speed bumps.

May 30, 2001

Dear Madam:

I promised to send to you some material on speed bumps. However, I didn’t have much for the surprising reason that there is not much law on speed bumps on public streets. There are a fairly good number of cases involving speed bumps on private easements and other private property, and a few cases on speed bumps on school grounds and similar places, but those do not translate well onto the public streets. Generally, MTAS over the years has pointed to an old Mississippi case, Mayor and Aldermen of the City of Vicksburg v. Harralson, 101 So. 713 (1924), as a cautionary note against installing speed bumps on general purpose public streets. That cautionary note has been justified, but your request was a good reason for me to update our research in this area.

Harralson, above is still good law in Mississippi. [See I.E. Parks v. City of Long Beach, 372 So.2d 253 (Miss. 1979), at 254, and White v. City of Tupelo, 462 So.2d 707 (Miss. 1984), at 709.] In that case, two speed “bumpers” had been installed by the city, apparently on streets generally open to the public. A Dr. Harralson claimed that striking one of them forcibly caused him to be thrown against the steering wheel of his car and injuring him. It was installed near an intersection to warn of the dangers of a collision there. The bumper was five inches high and five feet wide at its base. Dr. Harralson said that he didn’t know the bumper was there and that he didn’t see the sign (which announced “Bumper”) warning motorists of its presence, although he lived a very short distance from the site of the bumper, and evidence showed that he had passed the site several times before he was injured.

The Mississippi Supreme Court held as a matter of law that the city was liable for Dr. Harralson’s injury, reasoning that:

We do not think the city had the right to place a dangerous device or obstruction in its street making it unsafe, and which would likely injure persons traveling in automobiles over it. The purpose of the bumper was to bump and injure persons in automobiles crossing over it, even at a lawful rate of speed, who might fail to see it or become aware of its presence until they were so close that they would be unable to reduce the speed and prevent an injury when crossing it....A driver might be using reasonable care and not see the device, unless he was looking for it, because his attention might be reasonably and necessarily occupied with reference to other objects, vehicles, or conditions at that point; or he might in an unguarded moment of forgetfulness, even though he had previous knowledge that the bumper was located in that place, run over it, and be precipitated and bumped in his car, which jolt might under some circumstances of high speed cause great bodily harm and serious consequences....This scheme or method of warning drivers appears to us to be unreasonable, too drastic, and perilous for the purpose intended. The method of injuring one person in order to prevent danger to another is wrong in principle, as we see it, and is not such a reasonable regulation for the public safety as is warranted under the law, but is negligence. Creating one danger to prevent another is not in accord with the public safety–the very thing involved and desired. [Citation omitted] [At 714]

The logic of that case is still highly persuasive. Speed bumps on school grounds, housing and apartment complex streets, on shopping center property, and on other similar property, probably make more sense than on streets open to general public travel. Speed limits are expected to be low, and speed bumps are expected to be encountered, on such property.

Under the Tennessee Tort Liability Act, local government immunity from suit has been removed for injuries caused by “a defective, unsafe, or dangerous condition on any street...” [Tennessee Code Annotated, § 29-20-203]. While I can find no speed bump cases in Tennessee, it is easy to conclude on most general purpose streets they would create an “unsafe” or “dangerous” street. In Thomas v. City of Johnson City, 13 TAM 35-7 Ct. App. ES (8/23/93), the city was held liable for the injury to a child who struck a depression in the street while riding his bike. The depression was the product of a street excavation that had been backfilled. In addition, a city was held liable for injuries caused from the vertical offset of sidewalk pavement and brick pavers at the entrance to city hall, in Coln v. City of Savannah, 966 S.W.2d 34 (Tenn. 1998). It is difficult to see why a speed bump would be different than the depression or the vertical offset in those cases for the purposes of liability. Harralson makes the point that a speed bump is installed for the deliberate purpose of causing injury where the vehicle operator does not slow down sufficiently to accommodate the bump. In fact, Coln, above appears to adopt the Harralson line of reasoning when it declares that even though the danger from the vertical offset of the pavement and brick pavers was “open and obvious,” the risk of harm was “forseeable and unreasonable,” [my emphasis] because it was the only way into the city hall.

One case pointed to a manual I had not considered with respect to the legality of speed bumps on general purpose streets: the Manual on Uniform Traffic Control Devices (MUTCD). In Prell v. Sac County, 386 N.W.2d 89 (Iowa 1986), a person sued the county under Iowa’s Tort Liability Act for the county’s failure to install a rumble strip at a dangerous intersection at which he was injured in a collision. Iowa had adopted the 1978 version of the MUTCD, and question of whether a “rumble strip” was a traffic control device within the meaning of the MUTCD arose. The Court pointed to the Manual’s introduction:

Traffic control devices are all signs, signals, markings, and devices placed on, over, or adjacent to a street or highway by authority of a public body or official having jurisdiction to regulate, warn, or guide traffic. [At 4]

It then turned to Section 5C-2, which deals with the making of the ends of traffic islands: “These rumble strip sections provide increased visibility of the marked areas and produce an audible warning to vehicles inadvertently traveling across them.” [At 92]
The court also pointed to the “commonly accepted meaning” of the term “traffic control device”:

A control device usually either directs or regulates and a device means something that performs a function. It is common knowledge that rumble strips placed on the highway have the function of creating a noise to alert the driver of a danger ahead, normally a stop sign. [At 92]

All that was enough for the Court to determine that a rumble strip was a traffic control device. But the county in Prell escaped liability because the Iowa Tort Liability Act exempted cities and counties from liability for the installation of traffic control devices.

That is not true in Tennessee, where the Tennessee Tort Liability Act provides that:

Immunity from suit of a governmental entity [city and county] is removed for any injury caused by a defective, unsafe, or dangerous condition of any street, alley sidewalk or highway owned and controlled by such governmental entity. “Street” or “highway” includes traffic control devices thereon. [Tennessee Code Annotated, § 29-20-203] [My emphasis]

I am not sure that the Tennessee Courts would agree with the Iowa Supreme Court on the question of whether rumble strips or speed bumps are traffic control devices, but it seems a reasonable prospect they would. Under Tennessee Code Annotated, § 54-5-108, TDOT has the authority to adopt a uniform manual for traffic control devices that is mandatory for all governments in Tennessee. TDOT has adopted the 1988 version of the MUTCD. [Rules and Regulations of the State of Tennessee, § 1680-3-1 et seq.]

However, exactly what mandatory means within the meaning of Tennessee Code Annotated, § 54-5-108 and the MUTCD is not entirely clear. In O’Guinn v. Corbin, 777 S.W.2d 697 (Tenn. App. 1989), it was held that the installation of a traffic control device in the first instance was discretionary on the part of a county, and that local governments are immune from discretionary acts under § 29-20-205 of the Tennessee Tort Liability Act. The plaintiff argued that Tennessee Code Annotated, § 54-5-108 (under which the TDOT adopted the MUTCD) limited the discretion of the county with respect to where to put traffic control signs, in that case a stop sign. The Court declared that the MUTCD itself provided that stop signs should be put where they “may be warranted,” which preserved the county’s discretion as to where to put them. I can find no language in the MUTCD that makes mandatory any policy with respect to the installation of speed bumps or signs warning motorists and pedestrians of their existence. In fact, 2C-1 says of warning signs, “The determination of the sign or signs to be erected shall be on the basis of an engineering study using the following sections as guidelines. [There follows the provisions governing the kinds and placement of warning signs].

The introduction to the 1988 version of the MUTCD is identical to the 1978 version adopted by Iowa. But Section 5C-2 of the 1988 version of the Manual (as probably did the 1978 version) says more about rumble strips and devices closely akin to speed bumps:

Higher raised bars or buttons may be used in advance of islands having barrier curbs, but they should not be used where they constitute an unexpected hazard. These devices should not project more than 1-3 inches above the pavement surface, so that any wheel encroachment within the area will be obvious to the vehicle operator without a resultant loss of control of the vehicle. Where practical, such bars or buttons may be preceded by rumble sections, or their height should be gradually increased as approached by traffic. Pavement markings may be used with raised bars or buttons to better designate the island. [Emphasis is mine]

As far as I can determine, that is the only place in the MUTCD that rumble strips and higher devices akin to speed bumps are mentioned or authorized, and those “should not be used where they constitute an unexpected hazard.”

But it bears repeating that even if the initial decision to install speed bumps is a discretionary act for which a local government is immune under § 29-20-205 of the Tennessee Tort Liability Act, such speed bumps stand a very good chance of creating an “unsafe” or “dangerous” street under § 29-20-203 of the Tennessee Tort Liability Act.

The question of whether a city had an obligation to warn of speed bumps on a residential street arose in Neisen v. Village of North Bay, 463 N.W.2d 881 (1990–table) (unpublished disposition). There an 80 year old bicyclist claimed to have hit, and been injured as a result of, a speed bump installed by the city. The speed bumps were yellow plastic, ten inches wide and 2 inches high, and attached to the street by leg bolts. They did not cover the full width of the street; there was a distance of several feet from each end to the curb. The plaintiff argued that the city had negligently installed the speed bumps on the ground that no signs were erected that warned of their existence. The Court ruled in the city’s favor because under Wisconsin law, there were no statutes or rules or regulations regulating the installation of speed bumps or mandating signs warning of their existence. The decision of whether to install a traffic control sign, declared the court, was discretionary on the part of the city.

In theory, the Tennessee courts would go the same way as Neisen. As pointed out above, it has been held in Tennessee that the initial decision of whether to install a traffic control sign is discretionary [O’Guinn v. Corbin, 777 S.W.2d 697 (Tenn. App. 1989), Butler v. City of Dyersburg, 798 S.W.2d 776 (Tenn. Ct. App. 1990]. For that reason, arguably, a Tennessee city could install a speed bump unaccompanied by warning signage. That is not necessarily a foregone conclusion. Section 2C-1 of the MUTCD, says that:

Warning signs are used when it is deemed necessary to warn traffic of existing or potentially hazardous conditions on or adjacent to a highway or street. Warning signs require caution on the part of the vehicle operation and may call for reduction of speed or a maneuver in the interest of his own safety and that of other vehicles operators and pedestrians...

Section 2C-27 provides for BUMP and DIP signs. With respect to them, it says that:

These signs are intended for use to give warning of a sharp rise or depression in the profile of the road that is sufficiently abrupt to create a hazardous condition to cause considerable discomfort to passengers, to cause a shifting of the cargo, or to deflect a vehicle from its true course at the normal driving speeds for the road.

But nothing in that language appears to make it mandatory that a city or county install warning signs for impending speed bumps. Still, if speed bumps are to be used, it seems to me that advance warning of their location should be provided by signage installed in accordance with the MUTDC.

Enclosed is a good article from the City of Omaha, Nebraska, on the city’s speed bump programs. It does a good job of outlining the problems of developing good speed bump program. Note that both the police and fire departments objected to the use of speed bumps because of the impediments to law enforcement and fire service for various reasons. Indeed, it appears to me that the requirements of the program are bound to make more people mad than happy, but the article is favorable toward speed bumps under rigidly controlled circumstances.


Sidney D. Hemsley
Senior Law Consultant