This study has compared the safety of coaches in traffic with the safety of other modes of transport (passenger car, train and airplane) in the European countries Austria, Belgium, Germany, Denmark, France, the Netherlands and the United Kingdom, in the years 2007-2016.
The available road crash data did not allow to distinguish between coaches and public transport buses. Therefore, this study discusses the umbrella category “buses”.
The comparison of the safety of these transport modes was carried out by comparing risk. Vehicle risk is defined as the number of casualties per vehicle distance travelled (vehicle kilometres), and person risk is defined as the number of casualties per distance travelled by the vehicle occupants (person kilometres). In this report the casualties are fatalities: people killed in traffic within the borders of each relevant country. This also includes non-residents. Severely injured casualties were not included in this study.
The following data sets were used:
- Community Road Accident Database (CARE), maintained by the European Commission
- International Traffic Safety Data and Analysis Group (IRTAD), maintained by OECD
- European Statistics (Eurostat), maintained by the European Commission
- World Bank Open Data
These data sets were not always complete. Whereas the number of deaths for the investigated transport modes were available for all relevant countries for all of the years, this was not the case for the distances travelled by vehicles and vehicle occupants. When necessary, missing values were imputed, i.e. copied from the year before or after, or averaged if the data for both the year before and the year after were known.
For a fair comparison of the different transport modes, not only deaths among vehicle occupants – “inside-the-vehicle deaths” – but also “outside-the-vehicle deaths” (with that vehicle as the crash opponent) should be taken into account. This was only possible for cars and buses, and not for trains and airplanes. Therefore, only occupant deaths (“inside the vehicle”) could be used to compare the fatality risks of the four different transport modes. Especially for trains, this means that a large proportion (more than 85%) of the reported rail deaths was excluded; for these deaths it was not clear whether they were inside or outside the train or whether passenger trains were involved. Therefore, the calculated train fatality risk (the occupant risk) may be lower than the factual train fatality risk.
For airplanes, the crash in France in 2015 with 150 deaths among the airplane occupants was included in the Eurostat data set, even though it has been determined to have been caused deliberately by the co-pilot. This has a negative effect on the result for the safety of passenger airplanes.
To calculate the occupant risk from the vehicle risk, it is necessary to estimate the average number of occupants in each vehicle. For trains and airplanes, this could be calculated from the available data sets. For buses and cars, this was not possible and it was decided to use the values from an earlier study done in the Netherlands over the years 2010-2014 (p. 24, Temürhan & Stipdonk, 2016).
According to this earlier study, cars carry an average of 1.5 persons per trip and buses carry an average of 10.3 passengers per trip. This average includes public transport buses. A study conducted for the Royal Dutch Association of Transport Companies (KNV) reports 40 passengers on average in coaches over the years 2004-2015 (KNV, 2015). We assume that these values are sufficiently accurate for the risk estimate in this report.
Hence we assume 109 passengers per airplane, 127 passengers per train, 40 or 10.3 passengers per coach/bus and 1.5 persons (occupants) per passenger car.
The accuracy of the following results is therefore dependent on the correctness and limitations of the data sets and the assumptions that have been made.
The lowest occupant risk was found for train passengers, keeping in mind the probable underestimation due to the large group of rail deaths excluded. The risk for airplane occupants was similar, keeping in mind the relatively big crash in France in 2015 with 150 casualties affecting the results. The highest risk was found for car occupants. The occupant risk in buses was between that in cars and that in trains and airplanes.
If we take the occupant risk for buses to be 1, assuming an average of 10.3 bus passengers, the risks for occupants of the other modes of transport become:
Deaths inside the vehicle per billion person-km
In the bus: 1
In the car: 2.0
In the train: 0.14
In the airplane: 0.17
Given these risks, it seems safer to travel by bus, train or airplane than by car.
For buses, the Netherlands seems to have a relatively low number of road deaths among bus occupants compared to deaths “outside”, with a bus as the crash opponent (about 1 : 14); France seems to have relatively many road deaths among bus occupants, about 1 : 4.
For cars, the ratio between the fatality risk “inside the car” and the risk “outside the car” (with a car as crash opponent) is similar for all individual countries.
As was expected, buses appear to be more dangerous than cars related to casualties outside the vehicle. The reverse appears to be true for persons inside the vehicle. It is safer for the occupants to travel by bus, train or airplane than by car.