Priority Areas/ Accident Blackspots
3. IMPROVEMENT OF IDENTIFED ACCIDENT BLACK SPOTS AND PREVENTION OF LOSS OF LIVES THROUGH EFFECTIVE, CONSISTENT AND INTENSIVE CONTROLS
The “Accident Black Spot” term, used to express the road sections where the traffic accidents happen intensively in the world, is generally used to define the road sections with high intensity in a certain type of accident. In other words, road sections and spots where a certain type of accident is intensive, not all spots happening accident, are called accident black spots. In efforts made on ensuring traffic safety and decreasing the number of accidents, determining and improving accident blackspots gains prominence.
Preventing deaths and injuries in these road sections by eliminating accident blackspots is vital in terms of ensuring traffic safety. One of the points a comprehensive traffic safety strategy should focus is to ensure that accident black spots are no longer places where accidents constantly happen. When considering that the average lifetime of road infrastructure investments is 25 years, it is necessary to keep in mind that joint use of methods on ensuring road infrastructure safety with spatial analysis methods in which the distribution of traffic accident is depicted by previous years in the determination of accident black spots, and that the investments to be made in this field will maintain for many more years and not be limited with the implementation time of the 2021-2030 Road Traffic Safety Strategy Paper solely.
Several mathematical and statistical methods are used in determining the accident black spots, and the development of different approaches continue today. When examining the black spot identification efforts in some European Union Countries (Austria, Belgium, Germany, Hungary,
Denmark, Norway, Portugal, and Switzerland), one can see that, in general, black spot identification techniques based on accident number counting principle are used in these countries, and differently, black spots are tried to be identified by using models based on the Poisson distribution in Denmark, and Ampirik Bayes technique in Portugal.62 A statistical method named “Rate Quality Control Management” is used for the identification of such spots in Turkey, and the accident blackspots over the state roads across Turkey are identified.63
Furthermore, according to the Regulation on Highway Infrastructure Safety Management published in the Official Gazette dated 01.10.2018 and No. 30572 and put into effect, the method of identifying, analysing, and putting in order the road sections, being open to traffic for more than three years, and where a lot of traffic accidents involving death happen in proportion to the traffic volume.
Again, according to the efforts made, amongst the main places where accident blackspots occur are intersection, residential area passages, upwards downwards slopes, station fronts (such as fuelling stations), improper parts of infrastructure facilities, incorrect roads resulting from road engineering, areas with insufficient traffic signs and signalization, and ones with insufficient lighting.64 According to the results obtained from international efforts, the following table shows the accident-prevention potential of measures to be preferred in the improvement of accident blackspots:
|
Type of Measure |
Accident reducing potential (%) |
|
Highway Standards |
|
|
Enhancing road standard |
19-33 |
|
The increasing number of lanes |
22-32 |
|
Crossing lines between arrival-departure lanes |
40 |
|
Allocating lanes on turning right |
40 |
|
Traffic diversion |
20-40 |
|
Lowering speed from 70 km/hrs to 50 km/hrs |
10-30 |
|
Lowering speed from 90 km/hrs to 60 km/hrs |
17-40 |
|
Horizontal Alignment |
|
|
Improving road geometry |
20-80 |
|
Improving the curve radius |
33-50 |
Table: The Accident Prevention Potential of Measures to Take in Accident Black Spots
|
Type of Measure |
Accident-reducing potential (%) |
|
|
Improvement of Vertical Route in Highway |
||
|
Improving the height |
50 |
|
|
Passing lane |
11-43 |
|
|
Climbing lane |
10-40 |
|
|
Road Structure |
||
|
Lane extension |
12-47 |
|
|
Increasing antiskid protection resistance |
18-74 |
|
|
Shoulder extension |
10-40 |
|
|
Intersection Design |
||
|
Building shaking surface in the inner intersection areas |
40-95 |
|
|
Transition to T type of intersection from Y type |
15-50 |
|
|
Making right-turns in intersections fully-controlled |
45 |
|
|
Transforming uncontrolled intersections into rotary intersections |
25-81 |
|
|
Transforming intersections with traffic signs into rotary intersections |
25-50 |
|
|
Transforming uncontrolled intersections into rotary intersections |
40-47 |
|
|
Intersections allocated to turning |
10-60 |
|
|
Construction of roundabouts |
39 |
|
|
Construction of turning bay in urban roads |
30 |
|
|
Construction of turning bay in upstate roads |
45 |
|
|
Red sign cameras |
10 |
|
|
Conduct of traffic unit controls |
7-25 |
|
|
Traffic Control |
||
|
Lighted controls in intersections |
22-48 |
|
|
Placing directing lights in intersections |
14-58 |
|
|
Roadside lighting |
19-24 |
|
|
Increasing the visibility of lights and signs |
24-92 |
|
|
Stops signs |
47 |
|
|
Speed information signs |
23-36 |
|
|
Warning/information signs |
20 |
|
|
Reducing maximum speed |
16-19 |
|
|
Stop/Give way sign |
59-80 |
|
|
Stop sign |
33-90 |
|
|
Forbidding parking on the roadside |
10-25 |
|
|
Visibility |
||
|
Lane lines |
14-19 |
|
|
Roadside signs |
8-35 |
|
|
Yellow barrier signs |
24-52 |
|
|
Transforming the pavement sides into reflective ones |
6-18 |
|
|
Increasing lighting |
5-75 |
|
|
Type of Measure |
Accident-reducing Potential (%) |
|
Collision Preventing Measures |
|
|
Middle barrier |
14-27 |
|
Side barrier |
15-60 |
|
Fragile traffic signs |
30 |
|
Removing trees from upstate roadsides |
10 |
|
Improvement of boundaries in roadsides |
40 |
|
Improvements for Pedestrians |
|
|
Constructing pedestrian walks |
33-44 |
|
Constructing pedestrian crossings |
13-34 |
|
Uplifting the level of pedestrian crossings |
5-50 |
|
Constructing push-button pedestrian crossings |
21-83 |
|
Improvements in bicycles |
|
|
Bicycle lane arrangements |
33-56 |
|
Lighted arrangements in bicycle lane passages |
10-15 |
|
Putting forward the bicycle lane stop signs in intersections |
35 |
|
Facilitating Traffic |
|
|
Constituting areas with 30 km/hrs |
10-80 |
|
Shaking band lane strips |
27-50 |
|
Comfort breakers and ramps |
20-80 |
As part of the examinations held at micro-level of road sections and intersection spots where accidents happen with high-frequency within the scope of the management of accident black spots (Blackspot Management-BSM) to meet the safe, comfortable, and uninterrupted transportation need of road users, improvements were made by the DGH in a total of 1614 accident black spots and sections with high-potential of an accident between 2003 and 2019, and the number of accident black spots on which improvements were made in 2019 are 101. The following map shows the accident blackspots whose improvement plan was made in 2020:
Map: Accident Black Spots (DGH) Planned to Be Improved in 2020
As a result of examining the traffic accidents happening over the intercity roads in the period between 2014 and 2018, 2.755 road sections with intensive accidents were identified and efforts on preventing accidents even before they happened were made by concentrating the traffic controls in these road sections.
As a result of the examination made on a total of 84.638 traffic accidents involving death and injuries happening over intercity roads over the last three years, 1.477 road sections where intensive accidents involving death and injury happen were identified. The studies made showed that the total number of loss of lives in the last three years have been 902 and the injured been 27.731 in these road sections.
Similar “dynamic” efforts should be made related to the road sections where road accidents with “dynamic” features are intensive despite all efforts.
ACCIDENT BLACK SPOTS
STRATEGIC OBJECTIVE: Identification of Accident Black Spots in Intracity and Upstate Highway Network with Scientific Methods, Ensuring Improvement, and Preventing Loss of Lives Through Effective, Consistent, and Intensive Controls
GUIDING STRATEGIES AND SUGGESTIONS
1. Inspection of all roads within the scope of the basic principles of the safe system approach and the design of new roads according to this approach,
2. Applying the measures developed on the structure and perimeter of the road to the entire road network as part of the “Self-expressing and easy-to-adapt roads and forgiving road perimeter” approach,
3. Implementing the EU directive No. 2008/96/EC and themed “Highway Infrastructure Safety Management” in all roads,
4. Standardizing the road signs and signalizations including the roads under the responsibility of municipalities and testing the suitability for these standards,
5. With reference to the fact that the purpose behind improving the accident blackspots is to lower the social and economic costs of loss of lives, material damage, and traffic accidents, making affordable improvements in road sections with high traffic accidents intensity and to co-ordinately put into practice the other accident prevention methods such as controls, campaigns, training, information, and awareness-raising activities in cooperation with all other stakeholders as part of ensuring traffic safety,
6. The efforts on accident blackspots to be made by municipalities responsible for the urban roads,
7. Performing comparative analysis including international efforts and best example country practices in the efforts on improving accident blackspots,
8. Conducting in-depth research studies in all traffic accidents happening in accident blackspots and resulting deaths and serious injuries
9. Making available the database pertinent to conduct in-depth accident research to the full access of research teams.
GUIDING STRATEGIES AND SUGGESTIONS