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Visualisation of the exposure of cyclists to traffic on roads

Final Report Summary - VECTOR (Visualisation of the exposure of cyclists to traffic on roads)

The VECTOR project aimed at improving cyclists safety situation by assessing - and particularly, demonstrating - the actual exposure of cyclists to traffic-related fine particles in cities, using a novel tool in environmental monitoring, which combines real-time measurements and video-recording (RTV). The 'real-time visualisations' obtained in this manner clearly demonstrate cyclists' exposure in various traffic situations.

The main objectives of the VECTOR project were as follows.

Main goals:
1. to determine the actual exposure of cyclists to fine particles from traffic in a select set of different traffic-conditions in a number of European cities;
2. to inform cyclist interest groups, (local) authorities and the general public about the exposure risks of cyclists to fine particles from exhaust fumes;
3. to provide tools to improve the communication potential of scientific data.

Subsidiary goals:
1. to have cyclist interest groups, the general public and other important stakeholders better understand the risks of exposure to traffic related particles, with which they can better inform their members and convince (local) authorities to take exhaust-reducing measures if needed;
2. to provide tools to (local) authorities to decide on effective measures to reduce exposure of cyclists;
3. to stimulate the concept of science shops within universities and promote the importance of problems raised by civil society;
4. to promote the use of real time visualisation for communicating scientific data to non-scientists;
5. to provide students with the opportunity to gain experience in collaborating at a European level on a multidisciplinary problem raised by the civil society;

In great lines, the major activities in the project aimed at:
- measuring cyclists' exposure to ultrafine particles from traffic;
- presenting the results in an innovative way: 'real-time visualisations' (exposure graphs combined with video recordings);
- informing and 'activating' members of cyclists' associations, the general public and local authorities.

Concerning the latter point, the final aims were to:
- demonstrate personal exposure of cyclists to (ultra-)fine particles;
- demonstrate which traffic situations to avoid;
- demonstrate 'favourable' situations;
- advise cyclists and (local) policymakers on how to reduce exposure.

The measurement technique and set-up has been developed by Kooperationsstelle, with the help of internship students, and with advice of Fietsersbond. A condensation particle counter and a dust trak were used to perform the particle measurements (particle-counts and mass concentration, respectively). With respect to the particle-count measurements, only the particles smaller that 2.5 micrometre (PM2,5) were counted.

In addition, a small 'finger camera' and a global positioning system (GPS) system were obtained. In cooperation with the supplier of the PIMEX-software, the integration of measurement data and video recordings was fine-tuned. Finally, a measurement-bike was set-up which contained all necessary equipment. The measurement set-up was tested in a number of test-runs in Hamburg. After the first measurement campaign in Utrecht, September 2007, the method was further fine-tuned.

The measurements in the first two cities - Utrecht and Hamburg - were carried out in September and October 2007, respectively. After adapting for some technical problems, a number of successful measurements were made in both cities. In both cities, frequently used bicycle-routes were chosen, in which both busy and quiet parts of the city were passed. In addition to the measurements with the bicycle, a few measurements were made in a car, to serve as a reference.

On the basis of the experiences in the first two cities, Utrecht and Hamburg, the measurements in Budapest and Vilnius were planned. Criteria for route selection originally included:
- the routes should be actually used frequently by cyclists, i.e. routes connecting living areas, shopping centres and working or school and university areas;
- a variety of 'busy' and 'quiet' routes;
- a variety of traffic situations (e.g. with respect to the presence of traffic lights, roundabouts, etc., both combined roads for cars and motor vehicles and free cycling paths etc.).

In the first two cities, the length of the routes varied from 10 to 20 minutes. However, as there is always a factor of 'chance' that influences the actual traffic situation (how many cars pass, how many heavy trucks, how many mopeds, etc.), it was decided to be a little more 'selective' at the measurements in Budapest and Vilnius.

After finishing the measurement campaigns in all 4 cities, in total more than 400 km of measuring routes had been cycled and more than 20 hours of video material was collected. Supported by two students, the data were analysed and conclusions were drawn in cooperation with all partners. Illustrative video and measuring material for the project DVD, the website and external presentations was selected.

The analyses have resulted in a number of 'major conclusions', relating to exposure-modifying factors such as the impact of weather (wind, rain), the general design of a city, the car park (old versus new cars), disturbing sources of particles (e.g. fires), the local cycling infrastructure (road design, cycle lanes, green strips) and the placing of the measurement equipment:
- with the measuring set-up used, it appeared to be very well possible to visualise the personal exposure of cyclists to ultrafine particles, in specific traffic situations;
- the exposure to particles is higher when the cyclist moves closer to the motorised traffic;
- barriers between the road for motor vehicles and the cycle lane reduce the exposure;
- separated cycling lanes at a certain distance from busy roads for motor vehicles reduce the exposure significantly;
- external sources of particles, such as house fires or construction sites, may disturb the measurements and increase the exposure significantly;
- relatively old diesel vehicles or two-stroke engined vehicles (mopeds) increase the exposure significantly;
- frequently, cyclists are exposed to relatively short, high peak concentrations of ultrafine particles, which drop to the background concentrations relatively fast;
- however, ultrafine particle concentrations in cars show longer lasting high values - caused by particles entering through the ventilation system - which drop only slowly;
- the weather circumstances (heavy rain, wind) play a decisive role;
- highest exposures to ultrafine particles were measured in tunnels, street canyons (narrow streets with high building along) and underpasses;
- when the measuring equipment was placed on a low position - at children's height - higher exposures were measured.

As soon as all measurements had been done, the results were documented in a student's report (Ngengfak, '08; see 'Scientific output' on the VECTOR website ), in internal and external presentations, and on the VECTOR website. Major conclusions were shown at the final conference of VECTOR on May 13, 2009 in Brussels and at the international Vélo-city conference 2009 (found at online), and an article for the proceedings of this conference was produced.

Another major activity was the production of an instructive, 'self-explaining' DVD-tool with all project results. At the second project meeting in Utrecht, in September 2007, the contents of such a DVD had been extensively discussed - partly based on the advise that resulted from the pilot-study on the impact of real-time visualisations of exposure to the target group (Rosales Carreon, '07; see 'Scientific output' on the VECTOR website). One major conclusion was that the DVD should be 'self-explaining'. This means, that it was necessary to use a voiceover and / or texts in the images. A professional filmmaker was contracted, which carried out his work in close cooperation with ADFC and all other partners. Additional video shootings and interviews before camera were organised, and a 'the making of' film was produced, which explains the aims, methods, outcome and recommendations resulting from the VECTOR activities.

The final report contains a description of VECTOR, and in a concise form the main findings from the desk research, outcomes from the cyclist exposure measurements and real time visualisations (RTV), and the results from the validation of the awareness raising potential of the RTV ('communication experiment').

The report has been tuned to the interests of the cyclist interest groups, but will be of interest to researchers active in the area of air pollution or traffic planning, as well as for local, national and EU-level policy-makers in these areas.

The DVD contains a selection of 14 illustrative real-time visualisations of cyclists' exposure to traffic-related ultrafine particles in European cities, as well as an explanatory video that puts the RTVs into perspective. Besides, it contains a 'movie', presenting the issue of air quality in cities and cyclist's exposure, a short introduction of the equipment used and PIMEX (real-time visualisation), pictures of the cities involved and the routes measured, interviews with stakeholders, and statements explaining what local policy makers and individual cyclists may do. Thus, the DVD is 'self-explaining', meaning that target groups (cyclist interest groups, policymakers) will be able to understand the content without further accompanying explanations.

The project website has been established by ADFC, at online.

Project information

Grant agreement ID: 44671

  • Start date

    1 January 2007

  • End date

    30 June 2009

Funded under:


  • Overall budget:

    € 314 483

  • EU contribution

    € 314 483

Coordinated by: