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Structured road markings are becoming popular as edge line on high speed roads, ensuring night time visibility (retroreflection) during rain. These markings are often also "audio-tactile": vehicles (un)intentionally driving over it may produce much more tyre/road sound, which may be observed in the vehicle but also in the vicinity. The sound increase inside the car can be considered as a positive side effect, as it alarms the driver and may be very helpful for the prevention of "doze off" traffic accidents. The sound increase perceived outside the car however, may have a positive aspect as it can warn people on the emergency lane about the approaching vehicle, but it may as well annoy people living around. A method for the assessment of the acoustic properties of audio-tactile markings has been developed. It is mainly based on the "Close Proximity" (CPX) method, an ISO method intended for the acoustic assessment of pavements. The results of measurement campaigns with CPX trailers in Belgium and Germany according to a specially designed procedure are presented. The feasibility of the method is discussed. The research has been carried out in the frame of the standardization activities of the CEN working group CEN/TC226/WG2 "Horizontal signalization".
The goal of the project FIMCAR (Frontal Impact and Compatibility Assessment Research) was to define an integrated set of test procedures and associated metrics to assess a vehicle's frontal impact protection, which includes self- and partner-protection. For the development of the set, two different full-width tests (full-width deformable barrier [FWDB] test, full-width rigid barrier test) and three different offset tests (offset deformable barrier [ODB] test, progressive deformable barrier [PDB] test, moveable deformable barrier with the PDB barrier face [MPDB] test) have been investigated. Different compatibility assessment procedures were analysed and metrics for assessing structural interaction (structural alignment, vertical and horizontal load spreading) as well as several promising metrics for the PDB/MPDB barrier were developed. The final assessment approach consists of a combination of the most suitable full-width and offset tests. For the full-width test (FWDB), a metric was developed to address structural alignment based on load cell wall information in the first 40 ms of the test. For the offset test (ODB), the existing ECE R94 was chosen. Within the paper, an overview of the final assessment approach for the frontal impact test procedures and their development is given.
In 2011 399 cyclists died in road accidents in Germany and another 76.351 cyclists have been injured. Since 2000 the number of injured or fatally injured cyclists remained on the same high level. Cyclists form 19% of all casualties in German road traffic, although the modal split rate of this transport mode in 2008 was only 10% of trips and resp. 3% of kilometres per day. The high proportion of fatally and seriously injured shows the high vulnerability of cyclists. The demographic shift towards an older population in Germany and the governmental recommendation of increased bicycle use as an ecological, economical and healthy alternative to other modes of transport lead to the assumption that bicycle use especially of elderly people will increase. Based on these facts about the German cyclists' situation a representative survey of 2.000 cyclists was conducted. Results display use patterns and accident involvement on a descriptive level. Overall 7.7% of cyclists report to have been involved in at least one road traffic accident within the last three years. The performed path model analysis reveals an acceptable model fit. Though the explained variance of accident involvement of the applied psychological factors was low, significant relations between several of these factors and especially risky behaviour could be found.
Rural roads (highways) in Germany have to provide both high road safety and an appropriate level of service in accordance with their function in the road network. Single carriageway rural roads often underperform these expectations. An analysis of severe accidents on rural roads found two main contributing factors. First, high or inappropriate speed leads to accidents caused by the loss of control of the vehicle. Second, unsafe passing manoeuvres related to a misjudgement of sight distance, speed of oncoming vehicles or a misjudgement of the driver vehicle's acceleration capability. On the five roads where unsafe passing manoeuvres were a main contributing factor to accident occurrence, single short passing lanes (600 m to 1.2 km) were built to provide safe passing. On the remaining two-lane sections passing was prohibited by road signs and road marking. This paper investigates the effect of this design change on the accident situation and on traffic flow. The research project is based on a before/after comparison of traffic and accident data. Traffic volume, vehicle types and their velocities as well as the time gaps between the vehicles were recorded at different cross-sections. The result shows a significant improvement in road safety. This improvement was especially noted for severe head-on crashes, which were reduced to almost zero. The analysis of traffic flow on these roads pointed out that the chosen lengths of passing lanes were sufficient for safe passing and thereby reduced the need for dangerous driving behaviour. The recommendations of this research were fundamental for the determination of the design parameters of the second highest design class (EKL 2) in the new German Rural Road Design Guideline (RAL) published in spring 2013.
Offenporige Asphaltbeläge besitzen mit 22 % Hohlraum im Belag und einer groben Kornstruktur an der Oberfläche einen wesentlich anderen Aufbau als dichte Beläge. Nach vorliegenden Erfahrungen und Ergebnissen von durchgeführten Untersuchungen erfordern die Belagseigenschaften der offenporigen Asphaltbeläge eine andere Anwendung von Tausalz. Die Bundesanstalt für Straßenwesen (BASt) führte in den vergangenen Jahren gemeinsam mit der Firma KOMMZEPT-Ingenieurbüro Hausmann umfangreiche Untersuchungen zum Salzeinsatz auf offenporigen Belägen durch. Dazu gehörten Laborversuche, Messungen zur Verweil- und Wirkungsdauer von Tausalz auf diesen Belägen und Auswertungen der Beobachtungen von Autobahnmeistereien in Bayern, Brandenburg und Niedersachsen. Die Ergebnisse der Untersuchungen zeigen, dass die offenporigen Beläge teilweise winterdienstlich anders behandelt werden müssen als die dichten Beläge. Die Offenporigen Asphalte besitzen im Vergleich zu dichten Belägen eine deutlich rauere Oberflächenstruktur. In den Poren des Belags fließt Wasser nicht vollständig ab. Durch Kapillarwirkungen lagert sich Wasser im Belag ähnlich wie in einem Schwamm ab. Dieses Wasser im Belag kann durch den Verkehr sogar wieder zur Oberfläche gesaugt werden, an der es bei Temperaturen unter 0 -°C vor allem nachts zu einer Eisschicht kommen kann. Aufgrund der größeren gebundenen Wassermengen muss mehr Salz auf offenporigen Asphalten gestreut werden. Ausgebrachtes Tausalz bleibt länger in den Oberflächenporen oder im Belag haften. Es wird im Vergleich zu dichten Belägen durch den Verkehr fast nicht zur Seite verweht. Vorbeugend ausgebrachtes Feuchtsalz dringt langsam in die Oberfläche ein. An den eigentlichen Kontaktflächen zum Reifen bleibt wenig haften. Deshalb ist der Einsatz von Tausalzlösungen bei Reifglätte oder geringer Feuchte (Nieselregen) wirkungsvoller.
In the project SECMAN " SECurity MANual " a simple four-step procedure for the identification of critical road infrastructures, assessment of these infrastructures regarding various man-made threats and the determination of effective protection measures was developed. These methodologies are summarized and combined into a comprehensive best-practice manual which allows for a trans-national structured and holistic security-risk-management approach for owners and operators of road infrastructures in Europe. This paper presents the developed methodology starting from the assessment procedures of a network's criticality over an object's attractiveness and vulnerability to the selection process of appropriate protection measures.
The paper describes the development of transitions between different safety barriers in Germany but also in the context of the European standardization. In the paper practical and impact test expriences with transitions are shown. In view of the sheer number of theoretically possible combinations of safety barriers, the demand for testing every transition, even if the connecting safety barriers differ only slightly, appears to be economically unacceptable. On the other hand the experience from accidents and also from failed impact tests shows that transitions can be a risk to traffic safety. Therefore criteria for the distinction between transitions (impact test required/impact test unnecessary) are explained. In order to distinguish transitions which do not have to be impact-tested from those that require impact tests, criteria were developed and formulated.
The objectives of the FIMCAR (Frontal Impact and Compatibility Assessment Research) project are to answer the remaining open questions identified in earlier projects (such as understanding of the advantages and disadvantages of force based metrics and barrier deformation based metrics, confirmation of specific compatibility issues such as structural interaction, investigation of force matching) and to finalise the frontal impact test procedures required to assess compatibility. Research strategies and priorities were based on earlier research programs and the FIMCAR accident data analysis. The identified real world safety issues were used to develop a list of compatibility characteristics which were then prioritised within the consortium. This list was the basis for evaluating the different test candidates. This analysis resulted in the combination of the Full Width Deformable Barrier test (FWDB) with compatibility metrics and the existing Offset Deformable Barrier (ODB) as described in UN-ECE Regulation 94 with additional cabin integrity requirement as being proposed as the FIMCAR assessment approach. The proposed frontal impact assessment approach addresses many of the issues identified by the FIMCAR consortium but not all frontal impact and compatibility issues could be addressed.
For the assessment of vehicle safety in frontal collisions compatibility (which consists of self and partner protection) between opponents is crucial. Although compatibility has been analysed worldwide for over 10 years, no final assessment approach has been defined to date. Taking into account the European Enhanced Vehicle safety Committee (EEVC) compatibility and the final report to the steering committee on frontal impact [Faerber 2007] and the FP5 VC-COMPAT[Edwards 2007] project activities, two test approaches were identified as the most promising candidates for the assessment of compatibility. Both are composed of an off-set and a full overlap test procedure. In addition another procedure (a test with a moving deformable barrier) is getting more attention in current research programmes. The overall objective of the FIMCAR project is to complete the development of the candidate test procedures and propose a set of test procedures suitable for regulatory application to assess and control a vehicle- frontal impact and compatibility crash safety. In addition an associated cost benefit analysis will be performed. In the FIMCAR Deliverable D 3.1 [Adolph 2013] the development and assessment of criteria and associated performance limits for the full width test procedure were reported. In this Deliverable D3.2 analyses of the test data (full width tests, car-to-car tests and component tests), further development and validation of the full width assessment protocol and development of the load cell and load cell wall specification are reported. The FIMCAR full-width assessment procedure consists of a 50 km/h test against the Full Width Deformable Barrier (FWDB). The Load Cell Wall behind the deformable element assesses whether or not important Energy Absorbing Structures are within the Common Interaction Zone as defined based on the US part 581 zone. The metric evaluates the row forces and requires that the forces directly above and below the centre line of the Common Interaction Zone exceed a minimum threshold. Analysis of the load spreading showed that metrics that rely on sum forces of rows and columns are within acceptable tolerances. Furthermore it was concluded that the Repeatability and Reproducibility of the FWDB test is acceptable. The FWDB test was shown to be capable to detect lower load paths that are beneficial in car-to-car impacts.
For the assessment of vehicle safety in frontal collisions compatibility (which consists of self and partner protection) between opponents is crucial. Although compatibility has been analysed worldwide for over 10 years, no final assessment approach has been defined to date. Taking into account the European Enhanced Vehicle safety Committee (EEVC) compatibility and frontal impact working group (WG15) and the FP5 VC-COMPAT project activities, two test approaches have been identified as the most promising candidates for the assessment of compatibility. Both are composed of an off-set and a full overlap test procedure. In addition another procedure (a test with a moving deformable barrier) is getting more attention in current research programmes. The overall objective of the FIMCAR project is to complete the development of the candidate test procedures and propose a set of test procedures suitable for regulatory application to assess and control a vehicle- frontal impact and compatibility crash safety. In addition an associated cost benefit analysis should be performed. The objectives of the work reported in this deliverable were to review existing full-width test procedures and their discussed compatibility metrics, to report recent activities and findings with respect to full-width assessment procedures and to assess test procedures and metrics. Starting with a review of previous work, candidate metrics and associated performance limits to assess a vehicle- structural interaction potential, in particular its structural alignment, have been developed for both the Full Width Deformable Barrier (FWDB) and Full Width Rigid Barrier (FWRB) tests. Initial work was performed to develop a concept to assess a vehicle- frontal force matching. However, based on the accident analyses performed within FIMCAR frontal force matching was not evaluated as a first priority and thus in line with FIMCAR strategy the focus was put on the development of metrics for the assessment of structural interaction which was evaluated as a first priority.