Norwegian Public Roads Administration Research Articles

Does the improved stability offered by motorcycle antilock brakes (ABS) make sliding crashes less common? In-depth analysis of fatal crashes involving motorcycles fitted with ABS

ABSTRACTObjective: This research investigated the following issue. Though several tests indicate that motorcycle ABS may increase motorcycle stability, thus reducing the risk of a sliding crash involving braking (i.e., the rider is separated from the motorcycle and slides along the road surface prior to collision), there is limited research showing to what extent sliding crashes are reduced by ABS in real-life conditions.Methods: The Swedish Transport Administration (STA) and the Norwegian Public Roads Administration (NPRA) carry out in-depth studies for all road fatalities. A total of 38 in-depth studies with ABS motorcycles were included: 22 in Sweden and 16 in Norway (2005–2014). These were compared with 98 cases in Sweden and 32 in Norway involving motorcycles of the same types but without ABS. The data sets were analyzed separately and also merged together. The difference between the proportions of sliding crashes regardless braking was analyzed; selective recruitment was handled with a sensitivity analysis. Induced exposure was used to calculate the reduction of all crashes and those involving braking.Results: Four ABS cases (11%) involved falling off the motorcycle prior to collision, and 35% of the non-ABS crashes were sliding (P =.004). The sensitivity analysis showed that the results were stable, with a relative difference of sliding crashes ranging between 65 and 78%.None of the 4 sliding crashes with ABS occurred during braking; that is, all ABS riders who braked prior to collision crashed in an upright position. In the 4 sliding cases with ABS, the riders lost control of their motorcycles: 2 while accelerating on asphalt with very poor friction, 1 while negotiating a curve with an excessive lean angle, and 1 by abruptly releasing the throttle in the middle of a curve.Although based on a limited number of cases, the distributions of sliding and upright collisions among crashes without braking were similar, thus suggesting that the crash posture would not be affected by ABS if no braking occurred. The calculations with induced exposure showed that upright crashes with braking were also reduced by ABS; all fatal crashes, regardless of braking, were reduced by 52%.Conclusions: Though this research was based on a limited material, it confirmed that sliding fatal crashes are significantly decreased by ABS. Considering that ABS will soon be mandatory in the European Union on all new motorcycles with engine displacement over 125cc, these findings should be taken into account in the future design and testing of motorcycle-friendly road barriers and integrated protection systems.

Measuring bicycle braking friction in winter conditions

Bicycling is considered an attractive way of traveling and is becoming a more and more common mode of transportation in Scandinavia. However, winter conditions create a challenge for providing a high quality, functional bicycle road network. Winter maintenance actions, such as snow removal, gritting and salting, are needed. The Norwegian Public Road Administration (NPRA) sets standards for winter maintenance of cycleways, which includes a friction criterion. Friction measurement devices (FMDs) are used to test whether the conditions are within the specified standard. However, it is not known how well these values describe the friction experienced by bicycles. The two objectives of this study are: 1) to measure actual braking friction of bicycles in winter conditions and 2) to compare the results to friction measurement devices (FMDs). Two methods were used to measure bicycle friction in this study: deceleration and braking distance. Two instrumented bicycles with studded winter tires were tested by all-out braking tests on winter road surfaces. As a comparison, friction of the test stretch was measured by three FMDs. The results showed that both methods are suitable for defining bicycle friction; however, the deceleration was found to be a more accurate method in the given field conditions. The bicycles experienced the same or higher friction than the FMDs. The variability of bicycle friction was also greater than the variability of each individual FMD. This is probably due to lack of slip control of the bicycles and therefore it is uncertain whether maximum friction was in fact attained during the braking tests.

Weigh-in-Motion Equipment – Experiences and Challenges

The Norwegian Public Roads Administration focus on issues to improve weight controls, and the quality of statistic weigh data. An important part of the project is field tests of different methods and equipment for collecting Weigh-In-Motion (WIM) data, with high speed WIM equipment, and V2I communication where the vehicle reports its own weight. The tests are focusing on data quality (WIM vs static weight), user interface and usability, procedure and need for calibration and lifetime of sensors. Another important part of the project is the use of WIM data to pre-select vehicles at the control station. WIM data are combined with license plate numbers from ANPR cameras, and the measured weight is compared with the permitted weight. If a vehicle is overloaded then a warning is shown on the control station. This allows legal drivers to pass without being stopped.We have conducted several tests over a three years period. Two different WIM sensors technologies from four different manufacturers has been tested. The focus of the tests have been on accuracy, lifetime of sensors, calibration and usability of software and equipment. We have tested equipment for high speed WIM for pre selection of vehicles at control stations.Our results shows that lineas quarts sensors are better than piezo electric cables. The calibration procedures are time end cost consuming. Lifetime of the sensors are very short. This can be improved by deeper installation where it is possible. It is a problem that the accuracy of the sensors decrease over time. For one system the error in average gross weight increased to about 15% over a period of 6 months. The error in the other system had increased to 15% in three months, and after calibration the error increased to 15% in just over one month.A full scale test of a V2I system was conducted in Oslo in February 2015, as a proof of concept. One instrumented vehicle was used to verify the communication protocols. The information flow was steady and the focus was therefore on the reported weight. The internal difference in the self-declared truck weight for each axel was very low – with less than 1% difference between the test runs. Compared with the static weight the self-declared truck weight was approximately 5% too low. This was considered as a good start for the concept.A full scale tests with four vehicles are planned to start in September. The trucks will be equipped with communication units for sharing the current weight for a two month period. This setup will provide us with a wider basis for evaluating the data quality provided by the system. We believe that in the future WIM systems will be used together with V2I solutions, and that this will improve vehicle weight control further.The project is a cooperation between the Norwegian Public Roads Administration and the Traffic Engineering Research Centre.

Safe and Sustainable Coastal Highway Route E39

The project “Coastal Highway Route E39” have a mandate to, investigate how infrastructure can exploit renewable energy to reduce environmental footprint. Three PhD projects were initiated on this subject at Chalmers University of Technology by Norwegian public road administration. Results in this paper conclude that (1) Life Cycle Assessment should have a geographical dimension with respect to assumptions and input data, (2) there are substantial potential to reduce the CO2 emissions from the E39, especially when considering an electrification, and (3) the harvested energy from hydronic pavement system can be enough for maintaining ice-free roads in Nordic countries.

Coastal Highway Route E39 – Extreme Crossings

Coastal Highway Route E39 goes all the way from outside Trondheim in the middle of Norway following the west-coast down to Kristiansand. To be totally correct the E39 continues after a ferry from Kristiansand in Norway to Hirtshals in Denmark to the city of Aahlborg in Denmark.The total length of E39 along the coast of Norway is 1100 km. Today you can drive this route in approximately 21 hours, including 7 Ferry crossings. The goal of the project “Coastal highway route E39” (also known as the “Ferry Free E39”) is to make it possible to drive the distance in 13 hours and have fixed links instead of the seven ferries.The seven fjords has a width of 1.6 to 5 km, and depth of 400–1300 m, which means that the fixed links will be bridges longer and deeper than ever before.By using technology from Norwegian off-shore industry, especially the floating concrete oil platforms, we see that it is possible to anchor a floating construction on depths up to 1500 meter below sea level (mbs). We also know that we can have floating constructions; both bridges and submerged floating bridges (tunnels) are possible.Norway already has the longest road tunnel in rock (Laerdal tunnel 24.5 km), the longest subsea tunnel (Bomlafjord 7.8 km, Ryfast 14 km under construction 2014–17, Rogfast 27 km under construction 2016-) and the deepest subsea tunnel (Eiksundtunnelen 7.77 km long, 287 mbs). The public road network in Norway consist of 92,000 km roads, 17,000 bridges in operation and 1100 road tunnels, 35 of which is subsea tunnels. Norway also has 600 harbours and 51 airports (2014).From Norwegian industry, and overseas, we have had suggestions on how to solve the crossings. Three main concepts have been taken a step further; The Floating Bridge, The submerged floating tunnel and The TLP anchoring system (Tension-leg platform).We are now working on developing the concepts, which can be used separately or in combination in the crossings. The technology is now taken to a step where we shortly are able to start tendering (“Competitive dialogue” is the most likely tender).Also in the “Coastal Highway Route E39” we have been looking at Tendering options, Energy production and consumption of the constructions and the overall economy in the project (both normal financial calculations, but also “game changer”-effects of bigger markets). 31 PhD graduates are connected to the project. At the same time the Norwegian Public Roads Administration (NPRA) have ongoing research projects on materials, extreme weather, environment, energy, traffic safety, ITS and road technology in general.The presentation will focus on the newest developments in the extreme crossings, but also mention ongoing supplementary projects/PhD-studies at the time.

Why don’t cost-benefit results count for more? The case of Norwegian road investment priorities

The starting point is that the benefit/cost ratio is virtually uncorrelated to the likelihood of a Norwegian classified road project entering the list of investments selected for the National Transport Plan. The purpose of the article is to explain what pushes cost-benefit results into the background in the prioritization process. The reasons for their downgrading point to mechanisms that are at work not only in Norway. Explanatory factors are searched for in incentives for cost-ineffective action among planners, bureaucrats and national politicians, respectively, as well as in features of the planning process and the political system. New data are used to show that the road experts’ list of prioritized projects changes little after submission to the national politicians, suggesting that the Norwegian Public Roads Administration puts little emphasis on its own cost-benefit calculations. Besides, it is shown that the petroleum revenues of the state do not provide a strong reason for neglecting cost-benefit accounts. The overall contribution of the article is to offer a comprehensive explanation why professional and political authorities in Norway set road-building priorities diverging massively from those suggested by cost-benefit analysis.

Traffic accidents triggered by drivers at work – A survey and analysis of contributing factors

This report outlines the results of a study of severe road traffic accidents in Norway, triggered by drivers at work. The aim has been to examine whether and to what extent risk factors of these triggering drivers and their vehicles can be traced back to work-related factors. The study is based on data from the Accident Analysis Groups (AAG) of the Norwegian Public Roads Administration (NPRA), reports from The Transport Accident Investigation Board Norway (AIBN) and interviews with nine experts. The quantitative analysis of AAG data shows that too high speed for the circumstances, failure to use seat belt and insufficient information gathering were the most important risk factors in fatal accidents triggered by drivers at work. The qualitative analysis of reports from AIBN and expert interviews uncovered the following work-related factors considered central for traffic safety: follow up of drivers’ speed, driving style and use of seat belt, pay systems, safety culture, risk assessments, procedures/work descriptions and training. The AIBN reports and the interviews indicate that the following framework conditions influence traffic safety: time pressure, competition, type of transport, accident investigations/inspections. The majority of the interviewees held that work-related factors with potential implications for traffic safety are insufficiently monitored in controls and inspections.

Public road infrastructure inventory in degraded global navigation satellite system signal environments

Abstract Recent advancement of land-based mobile mapping enables rapid and cost-effective collection of highquality road related spatial information. Mobile Mapping Systems (MMS) can provide spatial information with subdecimeter accuracy in nominal operation environments. However, performance in challenging environments such as tunnels is not well characterized. The Norwegian Public Roads Administration (NPRA) manages the country’s public road network and its infrastructure, a large segment of which is represented by road tunnels (there are about 1 000 road tunnels in Norway with a combined length of 800 km). In order to adopt mobile mapping technology for streamlining road network and infrastructure management and maintenance tasks, it is important to ensure that the technology is mature enough to meet existing requirements for object positioning accuracy in all types of environments, and provide homogeneous accuracy over the mapping perimeter. This paper presents results of a testing campaign performed within a project funded by the NPRA as a part of SMarter road traffic with Intelligent Transport Systems (ITS) (SMITS) program. The testing campaign objective was performance evaluation of high end commercial MMSs for inventory of public areas, focusing on Global Navigation Satellite System (GNSS) signal degraded environments.

Improving walking conditions for older adults. A three-step method investigation.

The benefits of walking are widely recognized. In this regard, the Norwegian government has urged local authorities to develop walking strategies. The aim of such strategies is to influence a local walking culture and framework conditions for pedestrians. Older citizens are an important focus group because what is an accessible environment for them can be attractive for all groups. The primary aim of this study is to improve our understanding of how physical, social and individual factors affect whether older groups perceive that they need, can and want to walk. Second, we show how a mixed-method approach for collecting data gives an important input when planning a walking strategy. Combining quantitative and qualitative data gave deeper insights into how elders perceived their walking environment. The three steps (survey, participatory observation and workshop) made it possible to involve elders and practitioners from the municipality and the Norwegian Public Roads Administration directly in the study. This gave first-hand experience about how to facilitate the environment for older pedestrians. The findings suggest that the need, can and want dimensions of walking interact and reinforce each other. We find that measures affecting more than one such dimension seem to provide the best response for walking activity. This can be important for practitioners to take into consideration when developing good walking areas in the city.

Associations between driving under the influence of alcohol or drugs, speeding and seatbelt use among fatally injured car drivers in Norway

Since 2005, all fatal road traffic crashes in Norway have been analyzed in-depth by multidisciplinary investigation teams organized by the Norwegian Public Roads Administration (NPRA). During the period 2005–2010, 608 drivers of cars or vans were killed in road traffic crashes. Blood samples were collected from 372 (61%) of the drivers and analyzed for alcohol and a large number of psychoactive drugs at the Norwegian Institute of Public Health (NIPH). After coupling the analytical results with the NPRA crash database, 369 drivers with a fatal outcome were identified and included. Alcohol or drug concentrations in blood above the legal limits were found in 39.8% of the drivers who were investigated for alcohol or drug impairment; 33.9% had blood alcohol concentrations above 0.5g/L or concentrations of drugs above the equivalent Norwegian legal impairment limits or concentrations of amphetamines above 200μg/L. Among drivers with a fatal outcome who had been impaired by alcohol or drugs, 64.6% were unbelted and 71.7% were speeding when the crash occurred; whereas 24.2% and 33.2% of the sober drivers were unbelted or speeding, respectively. Statistically significant associations were found between impairment by alcohol or amphetamines and driving unbelted or speeding. Excessive speeding is one of the main reasons for road traffic crashes and together with being unbelted the main reasons for a fatal outcome. This behavior might in many cases be due to increased risk-taking or negligence of safety measures as a result of alcohol or drug use.

Cover Picture: Structural Concrete 2/2014

AbstractThe Norwegian Public Roads Administration started a programme named “National Tourist Routes in Norway” in 1994. Today it included 18 selected routes from south to north. The uniqueness of these attractions lies in the spectacular architecture found at the viewpoints, places of interest and visitor centres located amid magnificent scenery. The routes are carefully selected and allow tourists to enjoy some of the most spectacular scenery in the country. All are so unique that tourists automatically stop as they drive along, not just to admire the scenery, but also the special objects. Several of these objects are in concrete, and four are presented in the paper on pp. 117–128 in this issue (photo: Ole. H. Krokstrand).

Splendid concrete architecture in National Tourist Routes in Norway

AbstractThe Norwegian Public Roads Administration started a programme named “National Tourist Routes in Norway” in 1994. Today it includes 18 selected routes from south to north. The uniqueness of these attractions lies in the spectacular architecture found at the viewpoints, places of interest and visitor centres located amid magnificent scenery.The aim of the tourist routes was to strengthen Norway's position in the marketing of international tourism and to help promote local business.The routes are carefully selected and allow tourists to enjoy some of the most spectacular scenery in the country. Young Norwegian sculptors and architects, and a few renowned ones from abroad too, were invited to take up the challenge of creating unique viewing platforms, service buildings, footbridges, ramps, benches and stairs to be placed along the different routes. All are so unique that tourists automatically stop as they drive along, not just to admire the scenery, but also the special objects.Several of these objects are in concrete, and four are presented below. (Map references for the individual projects are listed for easy searching on Google Earth)

Klarspråk virker!

The Norwegian Public Roads Administration has documented the effect of rewriting letters in clear and concise language, and training the personnel in doing so. Every year, we at The Norwegian Public Roads Administration send out millions of letters to the Norwegian people. We realized that many of those receiving a letter simply did not understand its content, or what to do with the information provided in it. They needed help to understand, and contacted us. This resulted in us having an unnecessarily high number of cases where we responded to simple questions that the letters should have provided the answers for. What happened once we rewrote 10 of our standard letters and retrained our personnel? And what happened to the views of our 6,500 employees in the course of the plain language project? Over a period of time, The Norwegian Public Roads Administration has carried out four separate evaluations that show plain language works.

Cost-benefit Analysis for an ITS-solution based on Change in Consumers’ Surplus for the Users

The Norwegian Public Roads Administration (NPRA) is establishing a system (AutoPASS Travel Time System) that provides drivers with real-time travel times for some road sections. NPRA wanted to complete a cost-benefit analysis of such a system. The section considered in this study, i.e. Filipstad –Asker, has high traffic density during peak hours, often resulting in considerable delay. SINTEF Transport Research was invited to carry out this analysis, which was completed in January 2013. A user survey collected information on the travelers normal travel time and the delay that would result in a change of travel behavior. The road users were asked to state a critical level of delay causing a change in their behavior, for example stay home, change the time for travel start or change travel route. Traffic delay normally means a reduction in consumers’ surplus for the users of the road. To some extent travel time information allows the users to compensate for the reduction in consumers’ surplus due to traffic delay. The AutoPASS-system collects and delivers continuous data of the real time delay. This information tells us how often the travelers limit for changing travel behavior is exceeded within the period of evaluation. Each traveler has a unique normal travel time and a critical delay that will cause change in travel behavior. To make up for the difference in distance of travel the normal travel time was taken in to consideration. Using the method of consumers’ surplus the benefit from receiving information on travel time can be calculated. Such calculations were performed for one month in the autumn of 2012. The result from the calculations represents the benefit of not loosing time in traffic. The results from the evaluation from the section on E18 in Oslo Norway proved to be higher than the investment which means that the investment in the travel information system was right for society.

Selecting Road-Noise Abatement Measures: Economic Analysis of Different Policy Objectives

To satisfy new legislation, the Norwegian Public Roads Administration implemented a national facade insulation program encompassing 2,500 dwellings exposed to high levels of road traffic noise. Thereby, the road owner brought the equivalent noise levels from road traffic in compliance with a new indoor limit of 42dB. Cost-effectiveness analyses show that facade insulation was the least expensive noise-control alternative per dwelling. However, cost-benefit analyses show that the benefits were less than 20 per cent of costs. One reason for the poor benefit-cost ratio is that only the residents of the targeted dwellings benefit from at-receiver measures. Measures at the source and/or targeting the propagation paths also provide noise benefits for residents living along the same streets as the most noise exposed and inadequately insulated dwellings.

Will announcing seat-belt checkpoints reduce the non-use of seat-belts or increase other violations?

Abstract Road side interviews have been conducted in order to evaluate the use of a sign “Seat-belt enforcement” at seat-belt checkpoints of the Norwegian Public Roads Administration. Currently the checkpoints are usually well visible, but no information is given to the drivers about what kind of enforcement is being conducted. The results of the interviews show that more drivers become aware of both the checkpoints and the fact that seat-belt enforcement is being conducted when the checkpoints are announced with the sign. However, the results do not indicate that the subjective risk of detection for not using seat-belts increases, as has been the intention. Self-reported future seat-belt use increases when the sign is used, but since seat-belt use seems to be somewhat overreported, especially when the sign is used, it cannot be concluded that seat-belt use actually will increase. An undesired effect of the sign that has been found is reduced uncertainty and fewer drivers who assume or suspect that other violations than non-wearing of seat-belts are being enforced. The deterrence against other types of traffic law violations may therefore be reduced when the sign is used.

Developing new methods to cross wide and deep Norwegian fjords

The Norwegian coastline is rugged with long fjords, and exposed to wind and waves from the North Sea. The fjords represent barriers to crossing traffic, and thus also to industrial growth in the coastal regions. Because of the many ferry connections in coastal regions, the Norwegian Public Roads Administration has always been searching for new ways to cross the fjords by fixed connections. During the last years limits have been stretched with regard to the use of slender suspension bridges as well as long and deep sub sea rock tunnels. However, there are still many ferry connections left. These are the most extreme fjord crossings, where existing bridge building technology has to be developed further, and in addition, new knowledge and experience from offshore technology turns out to be of great importance.To develop new alternative fjord crossing methods, the Norwegian Public Roads Administration, Western Region, has organized a conceptual feasibility study of how to cross the wide and extremely deep Sognefjord. The experience from this study will be of great value to other fjord crossing projects as well. In addition, the study may be of interest to projects in scenic inland lake areas and urban waterfront areas. The feasibility study focuses on crossing alternatives based on the use of water as a bearing element of the bridge structures. It includes different crossing methods such as suspension bridges, floating bridges, submerged floating tunnels (SFT), and combinations of these.The results from these studies, with focus on the use of submerged floating tunnels, as seen from the owners point of view are discussed in the paper. The use of new technology raises questions with regard to safety of the structures as well as to the traffic. The study also gives important knowledge about where the different alternative crossing methods can meet local conditions on different crossing sites with regard to width and depth of the fjord, exposure to wind, sea waves, and ships traffic.

Economic appraisal of universal design in transport: Experiences from Norway

Economic assessment of universally designed transport projects has not been studied in depth in the transport planning literature. Universal Design (UD) refers to the design of transport systems in a way that they are accessible to all users, irrespective of the users’ abilities. This definition of UD has not yet gained roots in the transport economic literature. The conventional thinking is that UD is for the few, i.e., the impaired, and given that they are few in numbers, UD projects will generally be unprofitable from a socioeconomic point of view because benefits will be low while investment costs will be too high. The objective of this paper is to prove the opposite: UD projects benefit all users of the facility, whether impaired or not, and the additional costs of implementing them are generally low; hence, their net present values are high and positive. We build on collaborative work between the Norwegian Public Roads Administration (NPRA) and the Institute of Transport Economics (TOI) aimed at creating guidelines for assessing the economic merits of UD projects. Therefore, in this paper, we: (1) define how UD is to be understood in the context of road and public transport; (2) describe the types of benefits and costs that accrue to users if UD projects are implemented; (3) address how the benefits and cost can be valued in monetary terms; and (4) using three different types of projects, demonstrate that UD projects are surprisingly profitable from a socioeconomic point of view. Finally, we address the implications of our findings and explain why governments need to be concerned with UD of transport systems.

Cover Picture: Steel Construction – Design and Research 4/2009

AbstractThe Norwegian Public Roads Administration (NPRA) is widening the existing European Route E6 from two to four lanes over the stretch from Oslo's main airport, Gardermoen, and north to Lillehammer, the city that hosted the Winter Olympics in 1994. In the middle of the stretch there is a major intersection offering a choice between Norway's two biggest valleys, Gudbrandsdalen and Østerdalen. And here, at this remote site, stands Kolomoen Bridge, deep within dense evergreen forest but visible from afar in three directions via the road corridors through the forest.

Noise mapping of public roads in Norway: New calculation tool based on the Nord2000 Road Engineering Method

To comply with requirements in the Directive 2002/49/EC on environmental noise (END) and to national guidelines on land use and transport noise, the Norwegian Public Roads Administration has developed the calculation tool called NorStoy, which is composed of two main modules: 1. A calculation module with the Nord2000 Road Engineering Method algorithms. 2. An ArcGIS module to arrange the input data, delimit the calculation area, locate the calculation points and report the results. Nord2000 Road Engineering Model was completed in 2006, in cooperation with the Nordic countries. The model has very much in common with the coming joint European Harmonoise model. The challenge in using these models is to obtain an acceptable calculation time. To prevent NorStoy from stopping every time insufficient data occurs, we use default values based on either a typical mean value or the nearest registered value. At this time preparing input data is quite time consuming. We are able to produce the noise maps for the EC directive, but NorStoy is not yet an efficient tool for noise mapping in general. The development of NorStoy is still in progress.