Different approaches from the traffic engineering perspective

Transcription

1 Urban road safety Different approaches from the traffic engineering perspective ELTIS Training Budapest

2

3 Outline - Seminar schedule 1. Basic principlesofsafetypractice safety practice 2. Accident data 3. Road safety audit (RSA) 4. Local accident investigation (Black spot management) 5. Exercise Analyzing black spots 6. Road safety concept for the city of Dresden 7. Typical safety deficits in urban road networks 8. Exercise Safe design residential street

4 Mortality fatalities year person 7,0E 04 6,0E 04 5,0E 04 40E04 4,0E 04 3,0E 04 2,0E 04 1,0E 04 0,0E+00 Source: WHO Age Victims of infectious diseases Victims of vehicle and transportation t ti accidents Victims of killing and violent injury

5

6 rural roads, motorways new StVO speed limit 100km/h seatbelts in the front seatbelts in the back 130 km/h (freeways) use of helmets fine for not wearing a seat belt reunification speed limit (50 km/h) legal blood alcohol 0,5 legal blood alcohol urban streets source: Federal Statistical Office Germany

7 ROAD TRAFFIC HUMAN Environment VEHICLE

8 Accidents result of human failure? 95 % human failure in search of culprit compensation of damage for the victim for the person accused and traffic education

9 Main approach to traffic safety for traffic engineers Number and severity of accidents (un-) safety Understanding Engineering road users executives vehicle road enforcement regulations

10 Use of safety restraints in mechanical engineering Urban road safety

11 Safety potential and cause of accidents road human being Unfall accident environment vehicle tires darkness distraction narrow curve basic accident risk

12

13 Missing consideration of accident data NSM Accidents with fatalities with severe injuries Black spots Source: d

14 Group of Experts to advise the Commission on a strategy to deal with accidents in the transport sector Level Definition Examples Statistical data Collection of anonymous accident data - National statistics of collection elements that are used mainly for monitoring trends and priority identification. traffic accidents - CARE database at EU level Intermediate level Medium-level investigations between - Qualified police investigations the statistical and the in-depth, suitable for black-spot management report - Insurance reports In-depth investigations (independent as well as nonindependent) Detailed multidisciplinary investigations with a high number of variables (from several hundreds up to several thousand ). The aim is to prevent the re-ocurrence of serious accidents by discovering structural failures and proposing corrective measures. - CCIS in the UK - GIDAS in Germany Special accident investigations Multidisciplinary i li investigations with - Investigations conducted after the Mont- case-tailored methodologies. The aim is to prevent similar serious accidents by blanc fire in discovering structural failures and - A bus accident with 11 proposing corrective measures. fatalities occurring on 11 th June 2004 near Poitiers (France)

15 Accident-type maps (intermediate level investigation) local l occurrence of accidents in an urban street network

16 Accident-type 1 Driving accident (D) 2 Turning-off accident (TO) 3 Turning-into/crossing g accident (TC) 4 Crossing-over accident (CO) 5 Accident caused by stopping/parking (SP) 6 Accident in longitudinal traffic (LT) 7 Other accident (O)

17 collision diagrams accidents (I,D) 7 x type 3 2 x type 6 4 A(MI), 4 slightly injured Source: Merkblatt Teil 1

18 Road Safety Audit (RSA) A road safety audit is a systematic and independent investigation of safety deficits for construction projects. A safety audit places particular emphasis on the issue of road safety in the entire planning, design and construction process. In this way it is supposed to from a counterbalance to other issues that are connected to road planning (f.e. traffic flow).

19 Final aim: Road safety audit as part of an integrated quality management of road design Road safety audit sets focus on one objective: traffic safety Six objectives of road design Source: DVR 2004

20

21 Road Safety Audit (RSA) Source: DVR 2004

22 Most important audit phases with within built up area roads Preliminary planning, because it is still to be changed relatively easily and to be recognized the basic idea quite well on the other hand, Detailed design, After traffic opening, because in this layer the operational elements (marking, traffic signing, traffic signal control, lighting) are available, because the use and acceptance of the road users is recognizable.

23 Knowledge about safety levels of road facilities standard priority junction roundabout Accident cost rate - ACR [Euro/(1000Kfz*km)] Source: Eckstein/Meewes 2002

24 Partners in the audit process client designer auditor

25 Audit checklists Source: ESAS 2002

26 Audit process request from client, delivery of all documents to the auditor independent examination, possible site inspection and preparation of audit report delivery of audit report to the client, possible discussion of audit results decision on audit result by the client client accepts faults designer makes changes client does not accept faults client gives reasons in writing completion of audit phase

27 Benefit from Road Safety Audits 1 year accident diagram for all accidents Source: DVR 2004

28 Benefit from Road Safety Audits -> Audit results would have been Detailed design (1) Don t give way to left turners and pedestrians at the same time (2) Protect left turners by seperated phases (4 phase design) (3) Remove right-turn-on red signs Traffic opening (4) Additional overhead signals (30 cm diameter) are necessary (5) Don`t turn in signals, as this deteriorates recognition from greater distances

29

30 Local accident investigation Black spot management Repeat of accidents with similar characteristics is an advice on factors that cause accidents. There are local clusters of accidents where factors that cause accidents are existent. t Urban road safety Reduction or avoidance of one (local) factor increases the safety scope. A higher safety scope leads to less accidents.

31 Local accident investigation Black spot management Urban road safety

32 Source: Merkblatt Teil 2, 2001

33 poor perceptibility: signs are poorly visible, optical impression of a major or rather a through-road Point out/clarify Perceptibility and yielding by traffic signs and markings tt Teil 2, 2001 So ource: Merkblat

34 high traffic volumes on the major road and severe accidents So ource: Merkblat tt Teil 2, 2001 Traffic signals

35 Local accident investigation Procedure Source: Merkblatt Teil 1, 2003

36 Check for similarities Source: Merkblatt Teil 2, 2001

37 Check for local specifics - involved traffic streams - characteristics of conflict points S att Teil 2, 2001 ource: Merkbla

38 Site inspection Rural roads Junctions without traffic signals Turning-off accidents Conflict: Left turners and oncoming traffic Check for: - visibility of oncoming traffic - speed - traffic volume - accident severity Source: Merkblatt Teil 1, 2003

39 Measures - visibility, sight distance, traffic volume is ok - high speeds are the main contributing factor to this black spot measures that help against high speeds at junctions

40 Benefit Cost Ratio annuity factor investment costs recurring costs Source: Merkblatt Teil 2, Check for the most cost effective measure benefit-cost-ratio

41 Efficiency control Source: Merkblatt Teil 2, 2001

42 Safety concept for the city of dresden Starting point: 2500 injured people in road accidents / year Target: Reducing the number of injured people about 500 / a 3-year Concept with: - short- and mid-term strategies - long term safety program - priority of safety aspects in all planning projects

43 Strategies and procedures Action plan 1. Short-term strategies Local accident investigation 1. Year Quality assurance 2. Medium-term strategies Network Safety Management (NSM) Year Intermodal network analysis Road safety Audit Project End Final Report Recommendations and measures for further action

44 Short-term strategies 1. Local accident investigation Work of the accident commission (city, police) ( ) Comparison of the results Local accident investigation (university) ( ) Black spot ranking / priority it sequence Catalogue of measures

45 Short-term strategies 1. Local accident investigation 2. Quality management Vehicle safety: Investigation of the safety equipment of cars and cycles Safe way to school: Examination and evaluation of the existing official maps for the way to school Safety inspection: Review of the reports of the last 12 months, further training

46 Mid-term strategies 1. Examination of the major road network Network data: Sourcing and processing network data Network Safety Management: Evaluation of the safety potentials in the major road network

47 Mid-term strategies 1. Examination of the major road network Network data: Sourcing and processing network data Network Safety Management: Evaluation of the safety potentials in the major road network 2. Inter-modal Network analysis Analysis of single networks: basic deficits analysis of the networks for public transport, vehicles, cyclist and pedestrians Combination of single networks: Overlapping of single networks and detailed examination of the links

48 Mid-term strategies 1. Examination of the major road network Network data: Sourcing and processing network data Network Safety Management: Evaluation of the safety potentials in the major road network 2. Inter-modal Network analysis Analysis of single networks: basic deficits analysis of the networks for public transport, vehicles, cyclist and pedestrians Combination of single networks: Overlapping of single networks and detailed examination of the links 3. Road Safety Audit (RSA) Review: Analysis of audit reports and the belonging responses of previous audits Advanced training: Seminar on up-to-date topics of traffic safety

49 Typical deficits in urban road networks - Residential roads Safety deficits 1. (avoidable) traffic volume 2. excessive unadjusted speed 3. lack of sight Typical accident occurrences: 1. pedestrian, often child involvement in coherence with insufficient sight conditions 2. disregard of priority rules at intersections under insufficient sight conditions 3. damage concerning parking vehicles

50 Safety deficits measures (avoidable) traffic volume Source: Meewes 1987

51 Urban road safety Loop streets high curb illuminated bollard (lockable) Source: Pfundt, Meewes 1986

52 Safety deficits excessive unadjusted speeds speed v 85 [km/h] change in accident costs only signs single measure like markings strong measure humps, platforms Source: PVT 1995

53 Safety deficits measures excessive unadjusted speeds speed humps chicanes / lateral shifts Source: Meewes, Pfundt 1986

54 Urban road safety Safety deficits measures excessive unadjusted speeds priority (right of way) Operation and design of intersections priority to the right priority to the right, mini roundabouts roundabout distance Direction of driving

55 Safety deficits measures with no relevant effect excessive unadjusted speeds

56 Safety deficits lack of sight crossing pedestrians visibility of intersections poor parking management

57 Safety deficits lack of sight accidents crossing gs relative accident risk = ratio accid. / ratio cross. Source: Meewes 1979

58 Minor approaches improvement of perceptibility

59 Minor approaches improvement of perceptibility poor sight: parking vehicles, to the left or the right keep the sight triangle free of obstacles, if necessary use constructional measures like poles Source: Merkblatt Teil 2, 2001

60 Main roads Safety deficits 1. excessive speeds 2. no sufficient crossing aids for pedestrians 3. poor guidance of cyclists (especially at intersections) 4. insufficient design and/or operation (type) of intersections 5. unfavorable assignment of areas for parking and delivery

61 Urban road safety Supply crossing pedestrians traffic islands median strip /median reservation

62 Cross-section design no combination of minimum dimensions sufficient widths for non motorized road users cyclists close to the roadway (sight contact). Source: RASt

63 Typical accident-occurrences at intersections

64 Intersections Safety relevant demands visibility (early enough) perceptibility understandable driveable

65 Intersections

66 guiding of cycle facilities close to the lane time offset by: earlier begin of green time (1 2 sec) stop line closer to the intersection widened waiting lane for bicycles guiding of turning left cycles directly or indirectly mark crossings Source: ERA 19995

67 Intersections with traffic signal lights

68 Conclusion Raise a basic understanding di for traffic safety from the engineering i point of view (especially for road administration officials). Rules and regulations are important but not sufficient. Competence needs information o accident documentation o / maps. There need to be standard / formal safety practice procedures. Training of auditors and participants for local accident investigation (police, road administrations). Gain information on basis of accident analysis in you own country in order to judge safety levels for different types of traffic facilities