How to Acces, understand and use traffic accident data

Being able to access traffic accident data is helpful in order to substantiate subjective assessments of dangerous spots. When we use proven accident figures, chances are higher that local authorities will take action because they have to rely on factual evidence, not on subjective impressions.  

Possible use-cases: 

• Speed limits: introduction of 30 km/h zones in residential areas or particularly sensitive areas on heavy traffic roads. 
• Modification or redesign of dangerous junctions or road sections with accident hotspots or accident hotspot lines. 
• Restriction or complete ban of through-traffic on certain roads or road sections, e.g. conversion as a bicycle street, school street or as part of a neighbourhood block. 

Since 2016, the Federal Statistical Office² has been compiling all road traffic accidents recorded by the police in Germany and publishing this data online. This data is also visualised in the so-called Accident atlas – a digital map managed by Destatis. The atlas is updated annually and offers various filter options, for example by year and by type of road user involved in the accident. 

In addition to this official Accident atlas, there are various maps developed by third parties that are also based on data from the Federal Statistical Office. These often go into more detail and offer additional functions. Two such maps are the Accident map developed by Changing Cities and the Heatview, a service from Mitfahr|DE|Zentrale³.

💡 – Note:
Depending on the federal state, road traffic accidents may only have been recorded since 2018 or 2020. A more detailed explanation of the features of the Accident atlas, our Accident map and Heatview can be found in the next section.

Below you can find a detailed presentation of each traffic accident map. The main differences are: 

💡 – Note: 
If you have GIS skills or know someone who is familiar with geodata, you can also download the accident data as a data package and process it in GIS software for your own analyses. The data package contains significantly more details and can be combined with other data sets. You can find the download services here. 

The Accident atlas of the Federal Statistical Office is an interactive map on which accident data from all over Germany can be displayed and searched for directly in the browser. In addition to the mere visualisation, the following functions are available: 

• Filtering by type of road user involved in the accident (e.g. cyclist, pedestrian) 
• Information on accident frequency in road sections 
• Searching for addresses and locations 
• Exporting the map view in various formats (PDF, SVG) BUT: Filtering is only possible per year, a multi-year view is not available. 

If you need help using the Accident atlas, you can find instructions on how to use it here. 

The Changing Cities Accident map shows all accidents involving cyclists and pedestrians recorded since 2016 – including serious injuries (SV) and deaths (GT) – as a heat map. Zooming in on the map of Germany reveals the individual accidents. In addition, the service comprises an extension for each federal state in which accidents with minor injuries (LV) are also recorded. The accidents are colour-coded according to their severity: Dark red marks fatal accidents (GT), orange stands for seriously injured (SV) and blue indicates accidents with minor injuries (LV). 

In addition to mere visualisation, each of the Changing Cities maps offers the following functions: 

• Information on 
  • types of road users involved in the accident 
  • year of the accident  
  • day of the week,  
  • degree of injury,  
  • accident class and accident type, 
  • time of the accident 
• searching for addresses and locations 
• comprehensive filter options (e.g. by year, day of the week, degree of injury (including minor injuries), accident type, accident class and time) 

Heatview

Heatview.de is an interactive map service provided by Mitfahr|DE|Zentrale. Bicycle accident data and the average speed of cyclists can be visualised directly in the browser. Even though Heatview.de is rather heavyweight (i.e. depending on the connection and PC, long loading times may occur) and not quite as user-friendly as the other two map options, it offers a significantly higher level of detail and is very expandable. In addition to mere visualisation, the following functions are available: 

• accident information (accident type, accident class, accident category, accident year and whether a car is involved in the accident) 
• display of the average speed of cyclists (data of the Stadtradeln-campaign, prepared as part of the MOVEBIS research project) 
• identification of accident hotspots 
• additional evaluation according to the guideline “Merkblatt zur Örtlichen Unfalluntersuchung in Unfallkommissionen“ of the Forschungsgesellschaft für Straßen- und Verkehrswesen e.V. 

The data is displayed for a city or district. To select a district, you have to enter its AGS („Amtlicher Gemeindeschlüssel)“, a five-digit code, as the URL parameter (e.g. for the city of Berlin the AGS is 11000 https://heatview.de/?kreis=11000 ). 

💡 – Note: 
You can find more information about Heatview.de in the MFDZ Repository on Github⁴

In this section, you will find additional material which can be helpful if you want to use traffic accident data for actions, queries and campaigns.

You can take many steps on your own – but together we can achieve more! Get in touch to network and join in the discussion: info@changing-cities.org

You can draw attention to dangerous spots by sending a well drafted e-mail to the responsible road traffic authority. It is important that your message contains a precise description of the situation, provides facts and calls for concrete measures. 

Your e-mail should definitely contain: 

• Clearly identified location: Name the exact location in question. 
• Description of the situation: What does the infrastructure look like, how is it used? Are there any points of conflict, e.g. due to parked cars, lack of bicycle lanes, poor sight lines? 
• Observed hazards: What exactly happens and how often? Are there recurring problems? 
• Data-backed evidence: Check in our federal state Accident maps (see above), in Heatview (see above) or in the Destatis Accident atlas (see above) whether at this specific location there have been road accidents where people were injured in the last five years. 
• What should be changed: What specific measures are you calling for? Why would they make the situation safer (better visibility, less speed, clear traffic routing …)? 
• Legal situation: Make reference to the authority’s obligation to act (see § 45 StVO, Art. 2 GG and for Berlin possibly the Berlin Mobility Act). 
• Feedback request: Ask for a response and, if adequate, an on-site meeting. 
• Good to have (visual evidence): Photographs of the dangerous spot, screenshots from the Accident atlas or labelled map clips can be very helpful to illustrate the situation and highlight the need for action. 

Who is responsible for eliminating the causes of accidents?

In Germany, the central authority for investigating accidents is the Accident commission (Unfallkommission) of each federal state. „The Accident commissions have the task of recognising and evaluating recurrent accidents in the territory of the Federal Republic of Germany and deciding on measures to eliminate them.“ (Bundesanstalt für Straßen- und Verkehrswesen). The Accident commissions are organized at federal state level and can in some states be further subdivided into regional areas of responsibility. 

The Accident commissions base their actions on the procedural guideline Merkblatt zur Örtlichen Unfalluntersuchung in Unfallkommissionen (M Uko 2012) issued by the Forschungsgesellschaft für Straßen- und Verkehrswesen (FGSV). 

How are accident prevention measures developed? 

Before an Accident commission analyses the causes of accidents and recommends appropriate measures, it identifies accident hotspots (Unfallhäufungsstelle, UHS) on the basis of accident maps and a categorisation of accidents. 

The Accident commission uses two different traffic accident maps to identify recurrent accidents:

Accidents with minor injuries are hardly taken into account in the work of the Accident commissions: they usually only focus on serious accidents with fatalities or severe injuries. As a result, many dangerous spots where less serious but recurring accidents are taking place go unnoticed. This is why it is very important that committed people like you make use of the Changing Cities accident map to identify these overlooked accidents and build pressure for change. 

In which cases is a location considered an accident hotspot (in urban areas)? 

Accident hotspots are defined according to fixed threshold values. There is a distinction between accident hotspots (UHS) and accident hotspot lines (UHL).

Accident hotspots (UHS) (e.g. crossings, junctions) 

In urban areas a place is considered an accident hotspot if:

• within 12 months, there have been at least five accidents of the same type (light UHS) 
  or
• within 36 months, there have been at least five accidents with personal injury (minor injuries, serious injuries or fatalities) regardless of the type of accident (severe UHS)

Accident types⁵ are classifications where different types of traffic accidents are described based on their origin and typical conflicts. Only the traffic-related constellation of the accident is classified. 

For example: If a driver hits the brakes sharply because of a pedestrian crossing the road and as a result crashes into a stationary vehicle, this is not considered to be a car collision. The accident is rather classified as „crossing accident“ (accident type 4), as it was caused by the pedestrian crossing the road.

💡 – Note: 
Information on the accident type cannot be found in the Destatis Accident atlas (see above), but only in our own Changing Cities Accident map (see above), in the Heatview map developed by Mitfahr|DE|Zentrale (see above) and in the one- and three-year maps issued by the police. You can request access to these police maps for specific locations on the basis of the Freedom of Information Act (Informationsfreiheitsgesetz, IFG) (e.g. via the online service FragDenStaat.de). 

Accident hotspot line (UHL) 

In addition to single accident hotspots, there are also longer stretches of road where accidents occur and which are identified as accident hotspot lines. Such accident hotspot lines can hardly be found in cities due to the large number of junctions.

A road section is classified as an accident hotspot line if:

• within 36 months there have been at least three accidents of type 4⁶ (crossing accident) with personal injury and the distance between each of the accidents does not exceed 300m. 

This means: at least three accidents between a vehicle and a pedestrian on the road at a maximum distance of 300 m from each other within 36 months. 

💡 – Note: 
We at Changing Cities consider the criteria for accident hotspot lines to be outdated. The focus on accident type 4 – i.e. only on collisions between crossing pedestrians and vehicles – is insufficient. For a realistic assessment of cycling safety and, in particular, to record dooring incidents, we believe that at least accident type 5⁷ (stationary traffic) and type 6⁸ (longitudinal traffic) should also be included. 

How does the Accident commission decide on measures?

When developing measures, Accident commissions can refer to the “Digital catalogue of measures against accident hotspots” (MaKaU). This catalogue contains suggestions for a large number of “conflict types”. 

The measures can be divided into two categories: Immediate measures, which are to be implemented immediately after the analysis, and medium and long-term measures.

💡 – Note: 
The measures proposed in this catalogue are publicly available on the MaKaU website⁹. It is important to note that the measures can be helpful in standardised cases, but often do not adequately address the complexity of what is happening. 

What are the German government’s duties and responsibilities in terms of road safety? 

The government is obliged to ensure road safety in order to protect the lives and physical integrity of the citizens. This protection requirement is derived from the German Basic Law (Grundgesetz). (GG, Art. 2 (2)¹⁰.

In particularly dangerous situations, for example spots with recurring accidents or unclear road conditions, the road traffic authorities are responsible for traffic control measures such as individual speed limits, crosswalks or even 30 km/h zones. (§45 StVO Par. 1 1^st sentence¹¹| §45 StVO Par. 9¹²) 

Depending on each federal state, more specific regulations may apply in addition to the government regulations. You can find an example for Berlin below.

In Germany roads are assigned to different administrative levels depending on their category: Federal roads are the responsibility of the federal government, state roads are the responsibility of the federal states, while district and municipal roads are the responsibility of districts and municipalities respectively.

The Fernstraßen-Bundesamt¹³ is the competent authority for traffic regulations on long-distance roads such as highways (Autobahn) and federal roads. This includes, in particular, delegated powers such as the granting of certain permits and exemptions as well as the decision on traffic signs and traffic facilities. 

At the local level, the responsibility for regulations on main artery roads and secondary roads is organised in slightly different ways depending on the federal state. In most cases municipal authorities – i.e. authorities in cities, counties, municipalities or districts – are responsible.

How to find the right contact point:

💡 – Note: 
The quickest way to find the right authority is to do a Google search for „[name of your municipality] + road traffic authority“. The first result often provides the right contact details. Alternatively, you can contact your municipality or district administration for help.

In Berlin the Berlin Mobility Act provides for specific regulations that ensure road safety and define the authorities‘ duty to act. These regulations complement the government regulations and specify, i.a.:

• §10 Road safety¹⁴: Traffic should be designed to be safe and considerate so that everyone can travel safely. 
• §17 Road safety programme¹⁵: The authorities must take specific road safety measures, especially on school routes, accident hotspots and locations with particularly vulnerable people. 
• §21 Special measures¹⁶: After fatal accidents or at known accident hotspots, tests must be carried out to prevent further accidents. The results are made available online¹⁷. 

Another special feature of the Berlin Mobility Act is its clear focus on Vision Zero. A central guiding principle of the law is to reduce the number of serious and fatal casualties to a minimum in the long term. „Vision Zero“ serves as a guideline for all road safety plans and measures.

In Berlin it is the Berlin Senate, or more precisely the central road traffic authority of the Senate Administration, that assumes responsibility for the main artery roads: Verkehrsmanagement¹⁸. E-mail: verkehrsmanagement@SenMVKU.berlin.de. 

💡 – Note: 
You can often (but not systematically) tell whether a road is a main road because it bears the traffic sign 306 (priority road). The complete network of main roads as well as further information on road categorisation can be found on the website of Berliner Senatsverwaltung Mobilität, Verkehr, Klimaschutz und Umwelt¹⁹. 

For the secondary roads the responsibility lies with the road traffic authorities of the districts.

In Berlin the district authority (Straßenverkehrsbehörde) is a department of the Straßen- und Grünflächenamt. In addition to public roads, this “Roads and Green Spaces Office” is also responsible for public squares, protected parks, street and park trees, playgrounds, the district’s own allotment gardens, the maintenance of sports facilities and the district’s own cemeteries.

💡 – Note: 
Depending on the district, you will find more detailed contact information (telephone number, address) on the website of your district administration. It may also list contacts for specific topics or zip code areas in your district!