Pedestrian and bicycle bridges as examples of safe collision-free road crossings

Pedestrians are most at risk when they are crossing the road. This represents a significant proportion of all fatalities among pedestrians, amounting respectively to 50% in non-built-up areas and 75% in built-up areas. The most frequent reason for this accident is failure to give way. What is most terrible is that 30% of pedestrian accidents occurred at marked pedestrian crossings. Therefore, an important part of pedestrian safety management is selecting the right type of crossings, which are suitable for the conditions. At certain speeds and traffic volume, the only safe option for pedestrian crossings is to apply multi-level solutions, that is footbridges or tunnels. The paper presents examples of infrastructure redesign by constructing footbridges and hence, separating pedestrians and vehicular traffic to improve pedestrian safety.


Introduction and regulations
A European Transport Safety Council report published in June 2016 [1] points out to Poland as a country in which the number of road deaths per travelled vehicle-distance is the highest in the European Union.In 2015, 26% of all car accidents involved pedestrians and 14% involved cyclists.Hitting a pedestrian is the most tragic kind of accident on Polish roads.31.4% of fatalities are pedestrians.The largest number of pedestrian and cyclist accidents occurs in urban areas, however, the consequences of accidents which happen outside builtup areas are more tragic.More details about the situation on Polish roads may be found in the report of the Polish Traffic Police Service [2].This statistic shows that with such poor safety of vulnerable road users, it is imperative that programmes and actions are developed to protect pedestrians and cyclists.
Pedestrians are most at risk when they are crossing the road.This represents a significant proportion of all fatalities among pedestrians, amounting respectively to 50% in non-builtup areas and 75% in built-up areas.The most frequent reason for this kind of accidents is failure to give way.What is most terrible is that 30% of pedestrian accidents occurred at marked pedestrian crossings (see Fig. 1) [3].Therefore, an important part of pedestrian safety management is selecting the right type of crossings, which are suitable for the conditions.According to Polish law, pedestrians are allowed to cross the road as follows: -in any place, if far from the designated pedestrian crossing (the distance to the nearest crossing should be longer than that required by road traffic law), -at-grade pedestrian crossings (with or without traffic lights; with an "island"; with barriers defining a path for pedestrians), -collision-free grade-separated crossings in the form of a footbridge or tunnel.3 Case studies

Footbridge in Męcikał
The first example of a footbridge which saves human lives is the footbridge in Męcikał over the Brda river (Fig. 3).The structure was built in 2010, the details may be found in

Overpass for cyclists in Gdynia
The overpass for cyclists in Gdynia was opened in 2013 (Fig. 5

Conclusions
The principles and criteria for the choice of pedestrian crossing types are described in

Fig. 1 .
Fig. 1.Distribution of accidents with pedestrians on Poland's road network.Source: own study based on [3].

Fig. 2 .2
Fig. 2. Selection of the type of pedestrian crossings in urban areas.Source [3].
[6].The footbridge was built in response to the needs of local residents.It connects two places which are periodically visited by a significant number of people -a school and church.Before the new route was opened, people and cyclists were forced to use the narrow walkways on the bridge, along the road No. 235.The new footbridge is not only for the convenience of pedestrians but for their safety as well, because as we can see in Fig.1 4% of all accidents with pedestrians occur on sidewalks.The steel arch structure with a span of 42 m and full length of 58.46 m, improved safety of local pedestrians and cyclists, especially children walking to school.
[3].The author claims that to reduce the probability of pedestrian accidents the sources of danger related to time and space should be eliminated.This is why traffic lights, asylum islands, footbridges and tunnels must be constructed to move vulnerable road users to a different level than the road.Where justified, pedestrian bridges may be the best or only option available.The article presents examples of grade separated pedestrian crossings using different types of footbridges.The examples show the variety of forms and the space-making potential of engineering structures [12].The main advantage of pedestrian footbridges is that they separate pedestrians from road traffic.As a result, footbridges (and stopping pedestrians from crossing the roadway at-grade) may reduce pedestrian accidents up to 90%.The main drawback of collision-free crossings are their costs and their invasive character.The last example of a GFRP structure makes a faster, cheaper and environmentally friendly redesign of the infrastructure possible [9][11].Lightweight GFRP structures do not need extensive foundations, they are price competitive, do not need expensive maintenance and their manufacture, transportation and installation are much easier and faster compared to steel or concrete solutions.