Time filter

Source Type

Schepers J.P.,Center for Transport and Navigation | Heinen E.,University of Groningen
Accident Analysis and Prevention | Year: 2013

Governments aim to promote a shift from car to bicycle, but concerns about road safety seem to represent an important argument against this encouragement. This study examines the road safety impact of a modal shift from short car trips to cycling in Dutch municipalities. The road safety effect is estimated using Accident Prediction Models (APMs) that account for the non-linearity of risk. APMs are developed utilizing Negative Binomial regression. This study is the first to develop APMs using crash and mobility data from municipalities, and utilizing these models to estimate the effects of changing modal splits of current car and bicycle use to modal splits that actually exist in these municipalities. The results suggest that, under conditions such as in Dutch municipalities, transferring short trips made by cars to bicycles does not change the number of fatalities, but increases the number of serious road injuries. The neutral effect on fatalities, despite the high fatality risk for cyclists, can be explained by there being fewer cars on the road to pose a risk to others, the shorter length of bicycle trips compared to the car trips they replace, and the "safety in numbers" phenomenon. The rise in the number of serious road injuries is due wholly to the high number of cycling crashes with no other vehicle involved. The effect of a modal shift is dependent on the age of the population in which the shift is concentrated, and can be influenced by measures affecting cyclists' injury risk. © 2012 Elsevier Ltd.


De Gruijter D.,Ministry of Housing | Hageman E.,Center for Transport and Navigation
39th International Congress on Noise Control Engineering 2010, INTER-NOISE 2010 | Year: 2010

In the Netherlands it is commonly accepted that the cost of a noise barrier is much too high to solve a noise problem for just one house, but what about ten houses or a hundred? Therefore a cost-benefit analysis is part of the design process of noise measures. The cost of noise barriers, silent pavements etc. are weighted against the acoustic benefits. Up to now several methods were in use, each with different goals and merits, but also drawbacks. Now there is one new easy method for all purposes. The method is part of the new noise legislation for highways and railways.


Alberts W.,Center for Transport and Navigation | Alferez J.R.,Ministry of Development
Proceedings - European Conference on Noise Control | Year: 2012

On reviewing the END strategic noise maps produced by national road authorities in 2007, it became clear that the colours used by each member state to depict the various noise bands differed significantly across Europe. In order to standardize END strategic noise maps, it is recommended that each national road authority should follow a common approach to the colours used in noise mapping the major roads in their respective networks. Such a colour scheme should fulfil several considerations. It should cover a wide range of 5 dB noise band contours e.g., from 40 dB up to levels greater than 80 dB. All noise bands below 50 dB should be depicted with green colours and the colour red should be used to depict the noise band of 65-69 dB. Also, there should be sufficient differentiation between the colours to avoid problems with printed versions of the maps. Based on these considerations, a diverging colour scheme is recommended for the noise bands covering the range from 65-69 dB down to 35-40 dB. For noise bands greater than 65-69 dB and up to greater than 80 dB, a sequential colour scheme is recommended. This results in a proposal for a colour scheme to be used in END noise mapping for European major roads. © European Acoustics Association.


Alberts W.,Center for Transport and Navigation | Den Hollander M.D.,Center for Transport and Navigation
39th International Congress on Noise Control Engineering 2010, INTER-NOISE 2010 | Year: 2010

Integral acoustic management for Dutch motorways was introduced at Inter-Noise 2007. The Dutch national road authority (Rijkswaterstaat) uses integral acoustic management to deal with new developments in the field of traffic noise abatement. Now that our new noise legislation is waiting to be adopted by the Dutch Parliament, the next phase has been started. Highlights of the second phase are the implementation of the new noise legislation and the communication about it. This is necessary to get Rijkswaterstaat prepared for the new noise legislation before it comes into effect in 2011.


Hof B.,SEO Economic Research | Heyma A.,SEO Economic Research | van der Hoorn T.,Center for Transport and Navigation
Transportation | Year: 2012

A case is set up concerning a fictitious Dutch high-speed railway project involving passenger transport. Direct welfare effects are calculated using a standard transport model. On the basis of the case description and the direct effects, five models calculate total welfare effects and wider (indirect) economic benefits. The results of these models are compared. In very broad terms, differences in results can be explained, but on a more detailed level, differences remain that are hard to explain. We also find that large differences in results are caused by differences in the way direct welfare effects are calculated, instead of by differences in wider economic benefits. This suggests that it pays a lot more to focus on understanding and improving direct effect calculations than to try and perfectly quantify wider economic benefits. © 2011 The Author(s).


Hofman R.,Center for Transport and Navigation | The P.,Center for Transport and Navigation | Van Vliet W.,Center for Transport and Navigation
40th International Congress and Exposition on Noise Control Engineering 2011, INTER-NOISE 2011 | Year: 2011

Rijkswaterstaat tested a Poro Elastic Road Surface (PERS) on a service area of the Dutch A50. The aim was to construct a test section that; has an 8 dB noise reduction (Dutch Scale), a short construction time and could be tested during 3 years. The test sections was divided in two sections; the first having a dense sublayer (DAC16) and the second having a porous sublayer (PA16). The monitoring included noise measurements (CPX), skid resistance (Dutch modified RAW150-test) and breaking deceleration (Dutch DWW-test). The construction time was short, because the PERS was fabricated in a large hall and later as prefabricated construction rolled-out by using the Rollpave technique. The adhesion between PERS and both DAC16 and PA16 was good. The obtained noise reduction was slightly more than 8 dB The skid resistance and breaking deceleration directly after construction were below safety limits, because rainwater was kept in PERS like it is in a sponge. Consequently, the surface became wet and unsafe upon car passage. This unsafe condition remained during autumn and winter and test section could be opened in spring. Once opened the layer on the dense sublayer started to decomposed after a few weeks and test section had to be removed. Copyright © (2011) by the Institute of Noise Control Engineering.


Hofman R.,Center for Transport and Navigation
40th International Congress and Exposition on Noise Control Engineering 2011, INTER-NOISE 2011 | Year: 2011

Rijkswaterstaat, the Dutch State Road Authority, has the policy to use silent pavement on its entire road network. The main reason for focus on silent pavements is that they are relative cheap compared to other measures, like noise barriers, tunnels and sunk roads. Additionally, procedure time for construction allowance is high for traditional measures. For a new material such as Poro Elastic Road Surfaces (PERS) the advantage of cost effectiveness is not evident and has to be determined. Rijkswaterstaat made a simple calculation to exploit the life cycle costs of PERS. It turns out that the intrinsic materials costs of PERS is quite high, approximately 5 to 10 times more expensive than traditional asphalt. Therefore, product development has to focus on; cheap elastic materials, reasonable constructive strength/lifetimes under motorway conditions and high noise reductions of at least 10 dB (Dutch scale). Furthermore, the necessary budget increases rapidly when more lanes should have PERS; other alternatives, such as high noise barriers, might in the case of roads with multiple lanes even be more cost effective. Copyright © (2011) by the Institute of Noise Control Engineering.


Van Der Horst A.R.A.,TNO | De Goede M.,TNO | De Hair-Buijssen S.,TNO | Methorst R.,Center for Transport and Navigation
Accident Analysis and Prevention | Year: 2014

In The Netherlands, on bicycle paths, single-bicycle accidents, bicycle-bicycle and bicycle-moped accidents constitute a considerable share of all bicyclist injuries. Over three quarters of all hospitalised bicyclist victims in the Netherlands cannot be directly related to a crash with motorised traffic. As the usage of bicycle paths steadily increases, it is to be expected that safety on bicycle paths will become a major issue in the coming years in The Netherlands. A study was conducted into the behaviour of bicyclists and moped riders to improve traffic safety on bicycle paths. By behavioural observations with video, mutual conflicts and bicyclist behaviour on bicycle paths were recorded and analysed, among other things by means of the conflict observation method DOCTOR (Dutch Objective Conflict Technique for Operation and Research). The explorative phase of the study (phase 1), included two research locations, one in the city of Amsterdam and one in Eindhoven. The results gave guidance for a better understanding of the behaviour between different users of separate two-directional bicycle paths. An example includes the relationship between bicyclist-moped rider behaviour and the width of the bicycle path. For a condition with busy bicycle traffic in both directions the width of the bicycle path in Amsterdam (effectively 3.55 m) is relatively narrow, whereas the bicycle path width in Eindhoven (>4.94 m) appears to be sufficient to accommodate large flows of bicyclists. Because of a large flow of crossing pedestrians resulting in (severe) conflicts with bicyclists in Amsterdam, additional countermeasures to better control these interactions are needed. The DOCTOR conflict observation method from video appears to be applicable for conflicts between intersecting road users and for head-on conflicts on the bicycle path. Conflict situations between bicyclists in the same direction (constituting an important share of injury accidents on bicycle paths) require an additional and more general systematic observation of specific behaviour. Therefore, phase 2 of the project will focus in particular on interactions between bicycle path users in the same direction and underlying processes. © 2013 Elsevier Ltd.


Schepers P.,Center for Transport and Navigation
Injury Prevention | Year: 2012

Objective This paper examines the relationship between the amount of bicycle use and the number of single-bicycle crashes (ie, only one cyclist involved) in Dutch municipalities. Previous research has focused on crashes between bicycles and motor vehicles; however, most cyclists admitted to hospital are victims of single-bicycle crashes. Methods This correlational study used three data sets which included data relating to single-bicycle crashes and kilometres travelled by bicycle. Negative binomial regression was used to compare the amount of bicycling with the number of injuries incurred in single-bicycle crashes in Dutch municipalities. Results The likelihood of single-bicycle crashes varied inversely with the level of bicycle use. The exponent for the change in the number of single-bicycle crashes in response to changes in bicycle volumes was <1 in all analyses (ie, the increase in the number of single-bicycle crashes in a given municipality is proportionally less than the increase in the number of bicycle kilometres travelled by its inhabitants). The value was reduced in analyses of single-bicycle crashes with more severe injuries. Conclusions Cyclists are less likely to be involved in a severe single-bicycle crash in municipalities with a high amount of cycling. Given the large numbers of patients admitted to hospital as a result of single-bicycle crashes, it is important to include the risks of these in road safety and health effect evaluations, and to take into account the non-linearity of the relationship between single-bicycle crashes and bicycle use if road safety measures are to affect the level of bicycle use.


Ji Y.,Technical University of Delft | Ji Y.,Shanghai Institute of Technology | Daamen W.,Technical University of Delft | Hoogendoorn S.,Technical University of Delft | And 3 more authors.
Transportation Research Record | Year: 2010

Macroscopic fundamental diagrams (MFDs) exist in large urban networks in which traffic conditions are homogenous. They can be used for estimation of the level of service on road networks, perimeter control, and macroscopic traffic modeling. However, before the MFD concept can be applied, the factors that influence the MFD shape should be identified and their effects investigated. A microscopic simulation model is used to change conditions, that is, to derive MFDs under different conditions and for different types of networks. Results indicate that a relationship indeed exists between production and accumulation for the whole network as well as for parts of the network focused on freeway or urban links. MFD shape is a property not only of the network itself but also of the applied traffic control measures. At the same time, congestion onset and resolution lead to heterogeneous traffic conditions with congestion at specific locations in the network, resulting in loops in congested parts of the MFD. Investigation of the effect of traffic demand on MFD also indicates that rapidly changing traffic demands drastically affect MFD shape.

Loading Center for Transport and Navigation collaborators
Loading Center for Transport and Navigation collaborators