Advisory speed limit

An advisory speed limit is a speed recommendation by a governing body, used when it may be non-obvious to the driver that the safe speed is below the legal speed. It is a posting which either approximates the Basic Speed Law or rule (and is subject to enforcement as such) or is based on a maximum g-force exerted at a specific speed. Advisory speed limits are often set in areas with many pedestrians, such as in city centers and outside schools, and on difficult stretches of roads, such as on tight corners or through roadworks. While travelling above the advisory speed limit is not illegal per se, it may be negligence per se and liability for any collisions that occur as a result of traveling above the limit can be placed partially or entirely on the person exceeding the advisory speed limit.

Signposting of advisory speed limits varies from country to country; Australia makes extensive use of advisory speed limits across its highway networks while the Richtgeschwindigkeit ("reference speed") in Germany is valid for the whole autobahn network (but can be overruled by speed limits in particular sections or for special reasons like weather conditions or roadworks), while the United States and the United Kingdom only give advisory speed limits for hazards such as bends.

Advisory Curve Speed English 45
A U.S. advisory speed limit sign, warning drivers of a curve ahead.


Use of advisory speed limits varies by locale, but they are generally used to reduce speed along short stretches of dangerous road, such as on the tight curves of an off-ramp or on a busy shopping street. The advisory speed limit when not posted is generally the same as the mandatory speed limit in ideal conditions.


In Australia, if a person is involved in a single vehicle accident and the resulting investigation reveals that the driver was exceeding the Advisory Speed Limit displayed it can be a breach of the Insurance Cover Contract, resulting in no payout.

Advisory speeds in corners are set out in AS (Australian Standard) 1742.2-2009 Manual of Uniform Traffic Control Devices, Part 2, appendix F[1]. Corners are signed to indicate a speed at which lateral g-forces will not exceed 0.22g to fall well within the minimum suggested static rollover threshold of 0.35g for non-dangerous goods[2].


Now abolished German signs (in km/h) indicating the beginning and end of an advisory speed limit.

Zeichen 380-52 - Richtgeschwindigkeit 80 km-h, StVO 1992
Zeichen 381-52 - Ende der Richtgeschwindigkeit 80 km-h, StVO 1992

The Richtgeschwindigkeit (German Advisory or Suggested Speed of Travel) is a legal term in Germany describing the advisory speed limit for roads without a mandatory speed limit. Autobahns have an advisory speed limit of 130 kilometres per hour (81 mph) on non-signposted sections.

Exceeding the advised speed is not a criminal offense, but may result in greater liability in the case of a collision due to an increased danger of operating the vehicle.[3]

In Germany, the Autobahn-Richtgeschwindigkeits-Verordnung (Directive on Reference Speed on Motorways), introduced in 1974, recommends a speed of no more than 130 km/h (81 mph) for autobahns and similar roads, whose lanes are separated by a median or which have at least two lanes per direction, provided there are no traffic signs posting a lower speed limit.

Until 31 August 2009, a different reference speed could be posted by the traffic signs number 380 and 381, according to §42 of the German traffic code (Straßenverkehrsordnung, StVO), as seen above. As these traffic signs were only rarely used, they have been abolished, and will be fully removed by 31 October 2022.

New Zealand

Advisory speeds are not legal speed limits.[4] Advisory speeds end in 5 to avoid confusion with mandatory speed limits which end in 0. The limits are established at 0.22g lateral g-force[5] to fall well within the minimum static rollover threshold of 0.35g.[6]

United Kingdom

In the United Kingdom, most speed limits imposed by variable-message signs are advisory, and there are no sanctions for drivers who exceed them; a notable exception being the Gatsometer-camera enforced, MIDAS and ATM variable limits on the M25, M42 and M6 motorways.[7] Crucially, the signs imposing these limits are distinct from regular, advisory VMS displays by the inclusion of a red ring surround, effectively changing them from advance hazard warnings into standard, mandatory speed-limit signs.

As local councils require consent from the Department for Transport before changing speed limits, some use advisory speed limits on roads that the DfT refuses to officially downgrade.[8]

The usefulness of advisory speed limits has been questioned by a number of studies: one group from the Transportation Research Board found advisory speed limits through roadworks being consistently flouted by motorists,[9] while an investigation by Manchester Evening News found that almost all buses in Manchester city centre exceeded the local 10 miles per hour (16 km/h) advisory speed limit; some by as much as 30 miles per hour (48 km/h).[10]


The signage for advisory speed limits is not defined by the Vienna Convention on Road Signs and Signals, and is therefore not standardised internationally. The United States uses a small yellow sign under the main warning sign, as well as a standalone variation on the standard speed limit sign, with a yellow background instead of a white one, the words "speed limit" omitted and an additional panel stating the type of hazard ahead. Though they list speeds, the U.S. advisory speed signs are classified as warning signs, not regulatory signs, as primary speed signs are.[11] Australia uses a similar design as the U.S. in spite of regulatory speed limit signs being quite different. Germany used a square sign with a blue background and white lettering, similar to the minimum speed limit sign,[3] and New Zealand uses a yellow background with black lettering (similar to the Australian design without the "km/h" lettering). The United Kingdom currently uses an oblong white rectangle with black lettering stating "Max Speed".

Zeichen 380-52 - Richtgeschwindigkeit 80 km-h, StVO 1992

Most of Europe

Australia W8-2


Australia W1-9-1

Australia (motorway exits)

Australia W1-9-2 (L)

Australia (with diagram of motorway exit shape)

Australia road sign D4-V110 (R)

Victoria, Australia

Western Australia MR-WD0-1

Western Australia, Australia (traffic-calming bumps, known as speed bumps)

Québec D-110-P-2-65


Ontario Wa-32

Canada (Ontario) (highway ramps and exits)

Denmark road sign E39


Japan road sign 510 Safety Speed


Nederlands verkeersbord A4


New Zealand PW-25 (35 kmh)

New Zealand

New Zealand Permanent Warning - Exit Advisory Speed

New Zealand (motorway exits)

New Zealand PW-66 (2 chevrons right)

New Zealand (dangerous curve)

New Zealand PW-66 (4 chevrons right)

New Zealand (extremely dangerous curve)

New Zealand Permanent Warning - Truck Advisory Speed (right)

New Zealand (warning of danger of truck roll-over)



Philippines road sign W8-1


UK traffic sign 513.2

United Kingdom (imperial)

UK traffic sign 7294

United Kingdom (roadworks, imperial)


United States (customary)


United States (metric)


United States (highway exits)


United States (highway ramps)


United States (highway curves)

MDSHA W1-13(1)

United States (warning of danger of truck roll-over)


United States (integrated into curve warning sign)


  1. ^ "AS1742.2-2009 Manual of Uniform Traffic Control Devices, Part 2" (PDF).
  2. ^ "Mainroads Western Australia Static Rollover Threshold Calculator".
  3. ^ a b "Autobahnrichtgeschwindigkeitsverordnung" (PDF) (in German). German Federal Government. Archived (PDF) from the original on 29 September 2007. Retrieved 2007-10-28. Cite uses deprecated parameter |deadurl= (help)
  4. ^ "The difference between speed limits and suggested speeds".
  5. ^ "Heavy Vehicle Stability Guide, P.11" (PDF). NZ Transport Agency.
  6. ^ "Curve speed management July 2007 (Research Report 323, section 4)" (PDF). Land Transport New Zealand.
  7. ^ "Safer motorway driving". Department for Transport. Archived from the original on 2007-06-09. Retrieved 2007-10-28. Cite uses deprecated parameter |deadurl= (help)
  8. ^ "Speed limits". Bristol City Council. Archived from the original on 2007-10-17. Retrieved 2007-10-28. Cite uses deprecated parameter |deadurl= (help)
  9. ^ Pesti, Geza; Jessen, Daniel; Byrd, Patrick; McCoy, Patrick. "Traffic Flow Charactaristics of the Late Merge Work Zone Control Strategy" (PDF). Transportation Research Board. Archived from the original (PDF) on 2016-05-30. Cite uses deprecated parameter |deadurl= (help); Cite journal requires |journal= (help)
  10. ^ "Speeding buses put lives at risk". Manchester Evening News. 2005-04-26. Retrieved 2007-10-28.
  11. ^ Manual on Uniform Traffic Control Devices (2009 edition), Section 2C.06

External links

2007 M4 motorway coach accident

On 3 January 2007, a National Express Coaches Neoplan Skyliner N122/3L coach was operating on route 592 and was heading towards Aberdeen. It left Victoria Coach Station at 22:30 (GMT), carrying 65 passengers, and was due to arrive at Aberdeen Coach Park at 10:30 (GMT) on 4 January 2007. The coach was due to call en route at Heathrow Airport, Carlisle, Hamilton, Glasgow and Dundee.


The Autobahn (IPA: [ˈʔaʊtoˌba:n] (listen); German plural Autobahnen) is the federal controlled-access highway system in Germany. The official German term is Bundesautobahn (plural Bundesautobahnen, abbreviated BAB), which translates as "federal motorway". The literal meaning of the word Bundesautobahn is "Federal Auto(mobile) Track".

German Autobahnen are widely known for having no federally mandated speed limit for some classes of vehicles. However, limits are posted (and enforced) in areas that are urbanised, substandard, accident-prone, or under construction. On speed-unrestricted stretches, an advisory speed limit (Richtgeschwindigkeit) of 130 kilometres per hour (81 mph) applies. While driving faster is not illegal as such in the absence of a speed limit, it can cause an increased liability in the case of a collision (which the mandatory auto insurance has to cover); courts have ruled that an "ideal driver" who is exempt from absolute liability for "inevitable" tort under the law would not exceed Richtgeschwindigkeit.

A 2017 report by the Federal Road Research Institute reported that in 2015 70.4% of the autobahn network had only the advisory speed limit, 6.2% had temporary speed limits due to weather or traffic conditions, and 23.4% had permanent speed limits. Measurements from the German State of Brandenburg in 2006 showed average speeds of 142 km/h (88 mph) on a 6-lane section of autobahn in free-flowing conditions.


Bundesstraße (German for "federal highway"), abbreviated B, is the denotation for German and Austrian national highways.

Comparison of European road signs

European traffic signs present relevant differences between countries despite an apparent uniformity and standardisation. Most European countries refer to the 1968 Vienna Convention on Road Signs and Signals — it has been adopted by Albania, Austria, Belarus, Belgium, Bosnia and Herzegovina, Bulgaria, Croatia, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Italy, Latvia, Lithuania, Luxembourg, Montenegro, the Netherlands, North Macedonia, Norway, Poland, Portugal, Romania, Russia, San Marino, Serbia, Slovakia, Slovenia, Sweden, Switzerland, Turkey, Ukraine and the United Kingdom. The convention has not been adopted by Ireland, Moldova and Spain.

Comparison of MUTCD-influenced traffic signs

Road signs used by countries in the Americas are significantly influenced by the Manual on Uniform Traffic Control Devices (MUTCD), first released in 1935, reflecting the influence of the United States throughout the region. Other non-American countries using road signs similar to the MUTCD include Australia, Indonesia, Ireland, Japan, Malaysia, New Zealand, and Thailand. They are also the only countries listed here which drive on the left—with the exception of Liberia and the Philippines (though partial), both of which drive on the right.

There are also a number of American signatories to the Vienna Convention on Road Signs and Signals: Argentina, Brazil, Chile, Cuba, Ecuador, French Guiana, Paraguay, and Suriname. Of those, only Chile, Cuba, and French Guiana have ratified the treaty.

Mandatory action signs in the Americas tend to be influenced by both systems. Nearly all countries in the Americas use yellow diamond warning signs. Recognizing the differences in standards across Europe and the Americas, the Vienna convention considers these types of signs an acceptable alternative to the triangular warning sign. However, UN compliant signs must make use of more pictograms in contrast to more text based US variants. Indeed, most Pan-American nations make use of more symbols than allowed in the US MUTCD.

It is also worth noting that, unlike in Europe, considerable variation within road sign designs can exist within nations, especially in multilingual areas.

Comparison of traffic signs in English-speaking countries

This is a comparison of road signs in countries that speak majorly English, including major ones where it is an official language and widely understood (and as a lingua franca).

Botswana, Eswatini (Swaziland), Lesotho, Malawi, South Africa, Tanzania, Zambia, and Zimbabwe are all SADC members who drive on the left and use the SADC Road Traffic Signs Manual, and thus have identical road signs.

Dual carriageway

A dual carriageway (British English) or divided highway (American English) is a class of highway with carriageways for traffic travelling in opposite directions separated by a central reservation. Roads with two or more carriageways which are designed to higher standards with controlled access are generally classed as motorways, freeways, etc., rather than dual carriageways.

A road without a central reservation is a single carriageway regardless of the number of lanes. Dual carriageways have improved road traffic safety over single carriageways and typically have higher speed limits as a result. In some places, express lanes and local/collector lanes are used within a local-express-lane system to provide more capacity and to smooth traffic flows for longer-distance travel.

Fort Washington Way

Fort Washington Way is an approximately 0.9-mile-long (1.4 km) section of freeway in downtown Cincinnati, Ohio, United States. The eight-lane divided highway is a concurrent section of Interstate 71 (I-71) and U.S. Route 50 (US 50) that runs from west to east from an interchange with I-75 at the Brent Spence Bridge to the Lytle Tunnel and Columbia Parkway.Fort Washington Way is named after Fort Washington, a fort that preceded the establishment of Cincinnati. One of the city's first freeways, it was conceived in 1946 as the Third Street Distributor in conjunction with a major urban renewal project along the riverfront. It opened in 1961 after one of the most expensive road construction projects per mile in the United States. Fort Washington Way's complex system of ramps made it the most crash-prone mile of urban freeway in Ohio. During the late 1990s, it was rebuilt with a simpler, more compact configuration, improving traffic safety and facilitating the riverfront's redevelopment as The Banks.

Foyle Bridge

The Foyle Bridge is a bridge in Derry, Northern Ireland. The central cantilever span of the bridge is the longest in the island of Ireland, at 234 metres (767 ft), and the whole suspended bridge structure including the approach spans is 866 metres long (2839 ft).It crosses the River Foyle to the north of the city, and forms only the second of three bridges linking the city centre to the Waterside, the others being the Craigavon Bridge and the Peace Bridge walkway. Work on the bridge began in 1980 and it opened in October 1984. The seven approach spans on the east bank are of pre-stressed concrete box construction. The three main river spans are of steel box

construction and were built by Harland and Wolff shipyard in Belfast in 6

segments, weighed up to 900 tonnes each, and then transported by barge and oceangoing tug to site where they were lifted into position. Between 2003 and 2005 the bridge underwent strengthening, resurfacing and other improvements, leading to widespread traffic disruption in the city. Total cost of the refurbishment work was £10.6 million. The road was built to four-lane dual carriageway standard, and carries the A515. By 2004 more than 30,000 vehicles used the bridge every day.

The bridge was built for the Roads Service of Northern Ireland by RDL- John Graham (Dromore) Joint

Venture, with the consulting engineers being Ove Arup and Partners. The value of the four-year construction contract was £15,765,000. It was the first bridge in Ireland to be built according to a 'Design and Construct' system, whereby the same firm designed and constructed the bridge.

Road signs in China

A wide variety of road signs is displayed in the People's Republic of China. China's traffic signs also closely followed those used in the UK and Japan, China's traffic signs used Highway Gothic font just like the US.

Road signs in Italy

Road signs in Italy conform to the general pattern of those used in most other European countries, with the notable exception that the background of motorway (autostrada) signs is green and those for 'normal' roads is blue. They are regulated by the Codice della Strada (Road Code) and by the Regolamento di Attuazione del Codice della Strada (Rules for the Implementation of the Road Code) in conformity with the Vienna Convention on Road Signs and Signals.

Road signs in Mongolia

Road signs in Mongolia are similar to the Russian road sign system. They ensure that transport vehicles move safely and in an orderly manner, and inform the participants of traffic built-in graphic icons. These icons are governed by the Vienna Convention on Road Traffic and Vienna Convention on Road Signs and Signals.

Speed limit

Road speed limits are used in most countries to set the legal maximum or minimum speed at which road vehicles may travel on a given stretch of road. In the US they have been set to protect the public and regulate unreasonable behavior. Speed limits are generally indicated on a traffic sign reflecting the maximum or minimum permitted expressed as kilometres per hour (km/h) and/or miles per hour (mph). Speed limits are commonly set by the legislative bodies of national or provincial governments and enforced by national or regional police and judicial authorities. Speed limits may also be variable, or in some places unlimited, such as on most of the Autobahn in Germany.The first numeric speed limit for automobiles was the 10 mph (16 km/h) limit introduced in the United Kingdom in 1861. The highest posted speed limit in the world is 160 km/h (99 mph), which applies to two motorways in the UAE.There are several reasons to regulate speed on roads. It is often done to attempt to improve road traffic safety and reduce the number of casualties from traffic collisions. In the "World report on road traffic injury prevention", the World Health Organization (WHO) identified speed control as one of a number of steps that can be taken to reduce road casualties. This followed a report in which the WHO estimated that some 1.2 million people were killed and 50 million injured on the roads around the world in 2004.Speed limits may also be set to reduce the environmental impact of road traffic (vehicle noise, vibration, emissions) and as a political response to local community concerns for the safety of pedestrians. For example, a draft proposal from Germany's National Platform on the Future of Mobility task force recommended a blanket 130 km/h (81 mph) speed limit across the Autobahn to curb fuel consumption and carbon emissions. Some cities have reduced limits to as little as 30 km/h (19 mph) for both safety and efficiency reasons. However, some research indicates that changes in the speed limit may not always alter average vehicle speed.

Speed limits in Germany

General speed limits in Germany are set by the federal government. All limits are multiples of 10 km/h. There are two default speed limits: 50 km/h (31 mph) inside built-up areas and 100 km/h (62 mph) outside built-up areas. While parts of the autobahns and many other freeway-style highways have posted limits up to 130 km/h (81 mph) based on accident experience, congestion and other factors, many rural sections have no general speed limit. The German Highway Code (Straßenverkehrsordnung) section on speed begins with the requirement which may be rendered in English:

Any person driving a vehicle may only drive so fast that the car is under control. Speeds must be adapted to the road, traffic, visibility and weather conditions as well as the personal skills and characteristics of the vehicle and load.

This requirement applies to all roads, and is similar to the "reasonable speed" legal obligation levied in other nations.

Speed limits are enforced with a small tolerance. Driving merely 3 km/h (2 mph) or faster above the posted or implied speed limit is considered a punishable infraction in Germany. The speeding fines are set by federal law (Bußgeldkatalog, schedule of fines).

Speed limits in Switzerland

The general speed limit in Switzerland is 80 km/h (50 mph) outside and 50 km/h (31 mph) inside build-up areas. These limits were introduced in 1984 to protect the environment. On the motorways of Switzerland the limit is 120 km/h (75 mph). The limit on the similar autostrassen is 100 km/h (62 mph). There are lower limits for trucks and vehicles with trailers.

The Headrow

The Headrow is an avenue in Leeds city centre, West Yorkshire, England.

It is one of the most important thoroughfares in Central Leeds, hosting many of the city's civic and cultural buildings including Leeds Town Hall, Leeds Central Library, Leeds Art Gallery, The Henry Moore Institute and The Light. Some of the largest retail floorplates in the city are on The Headrow, particularly between Park Row and Briggate, where major chains have opened flagship stores. The Headrow is part of a longer axis that includes Westgate, Eastgate and Quarry Hill.

The Headrow forms a spine across the city centre between Westgate and Eastgate and is approximately ½ mile (700 m) long. It was widened between 1928 and 1932 in a redevelopment designed by architect Reginald Blomfield primarily as a way of improving traffic flow through city centre. The area has an advisory speed limit of 15 miles per hour (24 km/h). The section between Park Row and Briggate is reserved for buses and taxis and cars/motorcycles are not permitted to use it between 5am and 10pm.

Traffic stop

A traffic stop, commonly called being pulled over, is a temporary detention of a driver of a vehicle by police to investigate a possible crime or minor violation of law.

Traffic violations reciprocity

Under traffic violations reciprocity agreements, non-resident drivers are treated like residents when they are stopped for a traffic offense that occurs in another jurisdiction. They also ensure that punishments such as penalty points on one's license and the ensuing increase in insurance premiums follow the driver home. The general principle of such interstate, interprovincial, and/or international compacts is to guarantee the rule "one license, one record."

Yield sign

In road transport, a yield or give way sign indicates that merging driver must prepare to stop if necessary to let a driver on another approach proceed. A driver who stops or slows down to let another vehicle through has yielded the right of way to that vehicle. In contrast, a stop sign requires each driver to stop completely before proceeding, whether or not other traffic is present. Particular regulations regarding appearance, installation, and compliance with the signs vary by jurisdiction.

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