Jantzen C.,Bispebjerg Hospital |
Jorgensen H.L.,Bispebjerg Hospital |
Thomsen M.T.,Bispebjerg Hospital |
Riis T.,Bispebjerg Hospital |
And 3 more authors.
Danish Medical Journal | Year: 2014
INTRODUCTION: Different factors related to winter are known to influence the fracture incidence, but little is known about the effect of road surface temperature. This study examines the association between road surface temperature and the daily number of fractures in an urban area during two winters. MATERIAL AND METHODS: Retrospective data collection was conducted on all patients treated at Bispebjerg Hospital, Denmark, for a humeral, ankle, distal radius or hip fracture during the periods October to April 2009/2010 and 2010/2011. Patients were grouped according to age into the following categories: < 15, 15-30, 30-45, 45-60 and > 60 years. Data on road surface temperature (Tp.) were obtained from The Danish Road Directorate and grouped into the following categories: Days with Tp. > 0 °C, Tp. < 0 °C, Tp. > -5 °C, Tp. < -5 °C and ice alert (IA). RESULTS: A total of 4,892 patients (4,938 fractures) were treated during the study periods. The daily number of distal radius, humeral and ankle fractures increased significantly with decreasing road surface temperature and the presence of IA. For hip fractures no significant association was found. Decreasing temperature was associated with a significant decrease in the daily number of fractures for patients < 15 years, whereas patients > 30 years experienced a significant increase. CONCLUSION: Decreasing road temperature results in increased numbers of all fractures except hip fractures. Low temperatures is a risk factor for patients > 30 years and a protective factor for patients < 15 years.
Haustein S.,Technical University of Denmark |
Nielsen T.A.S.,The Danish Road Directorate
Journal of Transport Geography | Year: 2016
More targeted European policies promoting green travel patterns require better knowledge on differing mobility cultures across European regions. As a basis for this, we clustered the EU population into eight mobility styles based on Eurobarometer data. The mobility styles - including, for example, "green cyclists" and "convenience drivers" - differed not only in their travel-related variables but also in their socio-economic background, IT-affinity, and life satisfaction, with green cyclist showing the highest life satisfaction and two car-oriented styles having the highest socio-economic resources. In a second step, the 28 EU member countries were clustered into six country clusters based on their representation of mobility styles. The country clusters indicate the existence of considerably different mobility cultures across the EU. Sub-regions can be identified that have highly different positions on the path towards sustainable mobility and therefore different requirements towards European platforms and support measures, e.g. for 'Sustainable Urban Mobility Plans'. The country clusters can provide a starting point for future communication and targeting of European efforts in sustainable mobility. © 2016 Elsevier B.V.
Randleff L.R.,Hermes Traffic Intelligence |
Wanscher J.B.,Hermes Traffic Intelligence |
Holm J.,The Danish Road Directorate
19th Intelligent Transport Systems World Congress, ITS 2012 | Year: 2012
The Danish Road Directorate (DRD) has been gathering floating vehicle data (FVD) for several years1,2. The data is subsequently used to estimate travel times throughout the Danish road infrastructure. This has been used for both strategic decision making as well as for tactical planning support for the commuters through Internet route planning services and numerous other applications. Even though the floating vehicle data is processed in several phases to achieve very high precision the validity of the aggregated travel times is difficult to estimate. This paper describes an advanced tool developed for using regular floating vehicle data to visually depict and by standard statistic measures evaluate the aggregated results. Considerations related to developing the application and the extended processing of floating vehicle data for validation are described, along with the results of using the tool on real data provided by DRD.
Mollerup M.,The Danish Road Directorate |
Hansen S.,Copenhagen University
Journal of Hydrology | Year: 2012
Recently it has been shown that the Philip power series solution can also be applied for falling head ponded infiltration (Mollerup and Hansen, 2007) or more generally for variable head (VH) ponded infiltration on flat surfaces (Mollerup, 2007). In this study, it is shown that the power series solution can also be applied for VH ponded infiltration on sloping surfaces. Numerical simulations have been made for a Guelph Loam. For a VH scenario, the power series solution was compared with a 2D FEM-solution of Richards' equation with good agreement. Using the developed series solutions, a VH scenario was compared with constant head (CH) simulations with both a ponding depth of zero and the average ponding depth as used in the VH simulations. Especially the latter gave small differences in the cumulative infiltration compared with the VH results. Simulations showed that cumulative infiltration normal to the slope as function of time is decreasing with increasing slope angles for similar vertical ponding depths, corresponding to equal amount of surface water on a given horizontal slope section. In contrast, the infiltration on a given projected horizontal area increases with the slope angle. © 2012 Elsevier B.V.
Schmidt J.W.,Technical University of Denmark |
Schmidt J.W.,Cowi A/S |
Hansen S.G.,Cowi A/S |
Barbosa R.A.,Technical University of Denmark |
Henriksen A.,The Danish Road Directorate
Engineering Structures | Year: 2014
A large number of concrete bridges in Denmark have to undergo wide-ranging maintenance work to prevent deterioration due to aggressive Alkali Silica Reaction (ASR). This destructive mechanism results in extensive cracking which is believed to affect the load carrying capacity of the structure. However, sufficient knowledge concerning how it influences the structures load carrying capacity and stiffness is still lacking. In particular, more knowledge concerning the shear capacity of concrete slabs without reinforcement is needed. Often ASR deterioration result in demolition of the affected concrete bridges with considerable economical expenses as a consequence. A novel ASR test and measurement method, which can be used to perform shear testing locally on concrete bridges, is presented in this paper. Shear capacity testing is performed on a three span concrete bridge and several material test samples were taken from the test areas on the bridge deck. In addition, the test method is used to directly predict the shear capacity without disturbing the traffic significantly. Verification of the load carrying capacity of the bridge was the ultimate goal of the tests. A test rig, which could easily be moved between the slab test specimens, was constructed and the test areas were made in a way which enabled simple repair of the damaged areas after testing. In general, the novel test method worked very well since it provided an on site test method, which efficiently provides an evaluation of the load carrying capacity of the tested bridge. In addition, testing and monitoring provided important information concerning the shear behaviour of ASR deteriorated concrete. The results provided sufficient information to conclude that demolition of the bridge was not necessary and consequently significant savings related to the rehabilitation costs were obtained. © 2014 Elsevier Ltd.
Larsen M.A.D.,Technical University of Denmark |
Refsgaard J.C.,Geological Survey of Denmark |
Jensen K.H.,Copenhagen University |
Butts M.B.,DHI |
And 2 more authors.
Agricultural and Forest Meteorology | Year: 2016
In this study we develop and test a calibration approach on a spatially distributed groundwater-surface water catchment model (MIKE SHE) coupled to a land surface model component with particular focus on the water and energy fluxes. The model is calibrated against time series of eddy flux measurements from three sites of different land surface type (agriculture, forest and meadow) and river discharge data from the 2500km2 Skjern River catchment in Denmark. The approach includes initial calibrations of three one-dimensional models representing the three land surface types using the flux measurements for calibration. This step provides initial values for the subsequent modelling and calibration at catchment scale. To test the validity of the approach, two additional catchment scale distributed simulations were performed with no calibration and only calibration of the one-dimensional models, respectively. In addition, a subsequent validation period was simulated. A mean energy closure imbalance of 20% was seen for the three sites. For the distributed simulations, the energy imbalance was accounted for by two energy balance closure hypotheses ascribing the error to either energy fluxes or net radiation. In general, the distributed calibration approach improved model results substantially compared to using default values (no calibration) or calibration of the one-dimensional models only. For the distributed model simulations, the assumption regarding the energy balance closure had a substantial impact on the parameter sensitivities and on the simulated discharge and energy balance. During calibration, the simulation with corrected energy fluxes showed better performance on discharge than the simulation with corrected net radiation whereas the reverse was true for the validation period. Regarding energy fluxes, the simulation with corrected net radiation was superior in both the calibration and validation period. © 2015 Elsevier B.V.
Figenbaum E.,Norwegian Institute of Transport Economics |
Fearnley N.,Norwegian Institute of Transport Economics |
Pfaffenbichler P.,Vienna University of Technology |
Hjorthol R.,Norwegian Institute of Transport Economics |
And 8 more authors.
European Transport Research Review | Year: 2015
Introduction: This paper is concerned with incentives for the take-up and use of e-vehicles that are in place in different European countries. Especially, it analyses Norway and Austria, in order to establish and understand factors influencing the competitiveness of e-vehicles and potential market penetration. Norway currently enjoys the world’s largest take-up of electric cars per capita, achieved through an extensive package of incentives. Austria has used the concept of Model Regions with government support to stimulate market introduction. So far, this has been a less effective approach. Methods: The paper brings in and combine analyses of national travel survey data and web surveys to e-vehicle owners and non-e-vehicle owners. It considers socio-economic factors including convenience and time savings due to e-vehicle policies. Results: Analysing national travel surveys, we find a considerable potential for e-vehicles based on people’s everyday travel. Social networks play a crucial role in spreading knowledge about this relatively new technology. The take-up of battery electric vehicles correlates relatively closely with the user value of e-vehicle incentives. The fiscal effects of e-vehicle incentives are non-trivial – especially in the longer run. The cost of lifting a new technology into the market by means of government incentives is significant. We point to the importance of a strategy for the gradual phasing out of e-vehicle policies in countries with large incentives when the cost of vehicles goes down and the technology improves. Conclusions: Successful market uptake and expansion of electric vehicles requires massive, expensive and combined policies. Central government backing, long term commitment and market-oriented incentives help reduce the perceived risk for market players like car importers and allow the e-vehicle market to thrive. For countries with low e-vehicle market shares the potential is promising. Battery electric vehicles are already a real option for the majority of peoples’ everyday trips and trip chains. However, their relative disadvantages must be compensated by means of incentives – at least in the initial market launch phase. Diffusion mechanisms play a sizeable role. The lack of knowledge in the population at large must be addressed. © 2015, The Author(s).