It isn’t possible to ensure that all roads have the same degree of safety. The running speed over the road is the key determinant of the risk of accident and whether people will survive in case of an accident. We have the opportunity to save the lives of many people by increasing the safety level of the roads, avenues, and streets and determining proper speed limits to these road sections and ensuring the compliance of people.
As the non-compliance road behaviour is the leading fault causing traffic accidents more amongst the road user behaviours, identifying safe speed limits suitable for roads becomes one of the priorities. Besides, identifying risky road sections, where accidents occur in the road structure, signals that these are also the sections requiring urgent improvement in road structure.
Accurate planning is the first stage of a safe road network
The first field of application of traffic safety principles shapes in the planning, design, construction, and maintenance stages of the road network.
Right decisions should be made on where the priority areas of investment will be, for infrastructure arrangements are expensive and long-term investments. It is important to ensure a single standard in efforts to be made, and the construction and maintenance of the road according to these standards across the country. The construction of roads, describing itself as self-expressing roads, where all road users can understand the road standards on that road section with signs, signals, and lights should be the priority while determining the standards.
In the formation of residential areas and the construction of trading areas, the construction of roads to ensure transportation to these areas is essential. It is necessary to calculate the density of private and commercial vehicles for commercial areas and the activities of suppliers to transport goods for commercial transportation, and the demands on public transport vehicles. In residential areas, it is necessary to consider several matters such as the use of private vehicles in commutes to work, the routes and frequencies of public transport vehicles, the establishment of connections with the commercial spaces, schools, and sanctuaries.
The form of life of people shapes based on population growth and technological advancements. The infrastructure of the roads should be designed with the vision that transportation modes, enabling physical activity, including walking, and making them prefer public transport more will stand out, and enabling new transportation options.
Establishing a safe road system means to put into practice infrastructure arrangements proved to have protected human life
As road infrastructure arrangements require a high number of investments and are costly investments, they bring benefit to all road users in the long run when planned, designed, and managed properly.
According to the results of international researches, building flexible barriers in-between the two-way traffic running and roadside in road sections where vehicles with a high-speed run, may decrease mortality by 90%. Likewise, the traffic lines designed as rumble strips is 25% effective in decreasing all types of accidents and 42% effective in decreasing accidents resulting in death and happening as going off the road. Furthermore, the construction of roundabouts is effective in decreasing the accidents in available intersections and in ensuring safe crossing of pedestrians in elevated road sections.
In urban areas, the use of transportation methods putting forward the physical activities being more suitable for road users in terms of health is encouraged when environmental improvements, as well as safe infrastructure design, is ensured. Measures such as calming the traffic, separating walking trails and bike lanes with physical separators, strengthening the road lightings, and building walking trails are taken with this design.
Serious road infrastructure investment programmes are still applied in Turkey. While the general level of the road network is increased, the improvement of accident black spots and hot spots where traffic accidents exclusively happen frequently is ensured as a priority.
According to the Energy Theory put forward to prevent the happening of deaths and serious injuries resulting from accidents by William Haddon, accepted to be one of the important researchers bringing an analytic perspective to traffic safety important representatives of modern injury epidemiology; to prevent deaths and injuries in traffic accidents, it is suggested:94,95
As is seen, the recommended matters set forth the effect of road infrastructure and road perimeter, the safety of the vehicle, and the interventions after the accident on saving lives.
Safety improvement of bidirectional highways
Safety measures in bidirectional highways bear a special meaning in the context of the general safety measures to be taken in the highway system, and the measures to be taken in these roads are reviewed in the following groups:96
Prevention of vehicles to certain road sections and the adoption of speed lowering measures is prominent amongst the traffic calming measures, and it is possible to calm the traffic and increase traffic safety by putting into practice some other measures such as:97
through which the limitation of traffic flow speed within a residential area is endured with 30 km/hrs, and it is considered possible to ensure the safety of pedestrians and bicyclists with the speed limit below 30 km/hrs.
It is important to design and classify roads in a way to prevent humans from benefitting, and determine speed limits according to this classification
Roads have several functions, which are used by differed types of vehicles and have protectiveness at various levels. The design of urban roads in line with the use and protection of pedestrians and other vulnerable road users is a natural outcome of their functions. Establishing a hierarchical system between roads and the presence of infrastructure features pertinent to their intended use is also important in terms of the protection of road users. It is necessary to decide such matters as the land planning, detection of road sections where traffic accidents intensively happen, the condition of vehicle and traffic flow, behaviours of pedestrians, and the speed of the road in efforts made in this regard.
Critical progress was made in terms of the regulation on the road infrastructure safety management and the road infrastructure
The fundamental principles of road infrastructure safety management, impact assessment of road safety, road safety control, safety ranking and management of road network, and rules and procedures on the scope of road safety inspections, and the control the inspectors will make were determined as part of the “Regulation on Highway Infrastructure Safety Management” published in the Official Gazette dated 21.10.2018 and No. 30572. Accordingly:
The road safety impact assessment involving all necessary efforts for the cost-benefit analysis evaluating the information on road infrastructure safety to contribute to the decision of proper solution amongst options suggested by being performed in all road infrastructure project, and of different options.
The ranking of road sections with high accident intensity and the network safety ranking in traffic ways of road sections is made complying with the principles identified at least once every 3 years. The instalment of proper signals in road sections carried out maintenance works and threatening the safety of road users, and the signals having the feature to become visible during the day at night, and at safe distance is ensured.
In traffic ways, separate road safety inspections are conducted to determine matters on road infrastructure safety and prevent accidents.
These inspections are carried out periodically to;
The construction of roads to protect all road users was aimed at with the “Sustainable Safety” put into practice for road infrastructure safety. The following principles are followed in the entire road network according to this approach:
Classification of roads according to the functions they serve
Sustainable safe roads; are built divided into three categories according to the functions expected from the road; mobile roads, access roads, uniting roads.
Mobile roads; are roads generally ensuring fast and productive travel under safe conditions in longer distances. These roads can sometimes be considered as intercity state roads.
Accessible roads; are roads enabling safe mobility with low speed in settings where the vulnerable road users are frequently available, and access to places such as houses, shops, offices, companies, etc. with all the other traffic modes. Roads that require low speed and attentive cruising with short-distance vehicle traffic. It means the roads between train or tram stations and houses.
Uniting roads; interconnect the mobile and accessible roads with two different functions and systematic to one another, namely, describes the roads gradually ensuring the transition between rapid traffic and a road allowed to have a maximum speed of 30 km/hrs. Each road having only one function is of great importance in terms of road safety.99
In other words, all standards of use of standards of all roads serving the same function, including their horizontal and vertical signals, and speed limits are the same.
The vehicles to use the roads allocated by being classified by their elements such as volume, speed, and weight
It is the use of all harmonious vehicles, in respect of their speeds, size, and direction of travel, the same road whenever possible. Vehicles with big differences in terms of size, speed, and direction of travel shouldn’t use the same road according to this principle. In other words, buses or trucks, trucks and cars, the motorcycle shouldn’t use the same roads, moreover, the municipality buses to stop frequently and cards shouldn’t use the same road. Likewise, the vehicles to go straight ahead and the ones to turn left to not to use the same road is also included in vulnerable road users physically from vehicle traffic. In cases where physical separation isn’t possible, the speeds of all vehicles should be minimized, and the road structure should be supported with roundabouts and intersections with the elevated ground.
The comprehension of roads by everyone without needing another element thanks to construction standard and horizontal and vertical signalizations
The road users should easily understand how to act and how other road users may act from the physical structure of the road in a road section they have been for the first time. The use of same road standards and horizontal and vertical signs, and the road structure changing based on local conditions being in line with the standards is important to ensure this.
All physical structures, objects and, barriers that the road users may contact in the roadsides to be placed to not bring damage to humans
The structure of the road should be in a way to ensure injury as little as possible in case of an accident. It is necessary to remove these objects or structures with such features in road perimeters to prevent a vehicle from going off the road from crashing an object with sharp corners or pointed end. The forgiving road has a social meaning in Sustainable Safety; experienced drivers provide convenience and yield the right of way to drivers understood to be younger and inexperienced. Thus, the punishment of inexperienced drivers through death and injury as a result of an accident is prevented with this method.100
Best Practice Examples on the Contribution of Infrastructure Arrangement to Traffic Safety
Practice Example 2. Highway Network Safety Management Approach
Highway Network Safety Management is an approach that was jointly developed by the Federal Highway Research Institute (BAST) in Germany and the Ministry of Environment in France, Technical Department of Transport, Highway, Bridge Engineering, and Traffic Safety (SETRA). Highway Network Safety Management approach is a system enabling the detection of road sections required to be primarily improved for institutions responsible for the construction and maintenance of roads.
The safety potential of road is examined in this approach. The financial size of the accidents happening is identified with the safety potential and the financial damage caused is calculated, the expenses to be made in case the same road section is constructed with the best infrastructure investment possible is calculated, then it is decided that the more the gap there is, the more urgent it is to improve the specified road section. The positive aspect of the Highway Network Safety Management approach is that it enables the analysis of different types of road according to the classical accident perimeter road improvement approaches.101
Practice Example 3. 2+1 Roads
The safety standards of the single-platform roads used by bidirectional traffic was decided to be raised in Sweden by 2025. Within this scope, the cable-type median strip barrier practice was adopted between traffic lanes to prevent the head-on collision of vehicles using such roads as of 1998. As part of these improvements, 13 meters wide conventional roads were started to be redesigned by standards called “2+1” Road”.
In “2+1” Road” road design, the roads are constructed as two going lanes, and one coming lane, or vice versa. The two lanes continue around 2 km and after creating a road section to overtake the vehicle in front, the two lanes are reduced to single lane, this time the road platform used by the oncoming traffic is transformed into two lanes, and the passing lane is provided for oncoming vehicles to overtake safely. The head-on collision of vehicles is prevented as the traffic in opposite directions is divided with the safe barrier system, speeding for a long time isn’t permitted, for the 2+1 system is alternately continued with intervals of 2 km each, and the driver is ensured to pay attention to the road. The Sweden model is suggested by international organizations for road sections to not be transformed into speedways, and roads in rural areas. Aforesaid roads have had serious contributions in decreasing traffic accidents in Sweden.102
Practice Example 4. EuroRAP Programme
The European Road Assessment Programme (EuroRAP) is an international credit-rating non-profit organization and was set up in 1999 taken example by Euro CAP assessing vehicles with safety features and star rating. EuroRAP assessments are conducted in three ways:
Risk Maps: Risk-rating is conducted by sorting roads according to colours by million vehicle-km measure and number of loss of lives..
Performance Monitoring; is to assess the development by following up the measures to decrease loss of lives happening in roads.
Safety Rating: The determination of to what extent does a certain road section provide protection to people inside the vehicle in case of an accident.
The roads are rated between 1 to 4 by pursuant to this assessment. 103
It is considered that the preparation and adoption of a programme similar to the EuroRAP Programme by competent bodies in Turkey, and thus rating the roads will make contributions in many fields involving accident prevention and post-accident interventions.
INFRASTRUCTURE: ROAD AND ROAD PARAMETER
STRATEGIC PURPOSE: Enhancing the Safety Standards of Infrastructure, Road, and Road Perimeter, and Contributing to Traffic Safety
GUIDING STRATEGIES AND SUGGESTIONS
Promoting innovative technologies of the era and information systems, and road transportation services, using energy productively, making use of renewable energy resources maximally and thus damaging the environment minimally, and equipped,