Transport Research Arena 2014, Paris Developments in tolling by weight David Cornu a, Christoph Gilgen b, Hans van Loo c a Head of SBF Road & Traffic, Kistler Instrumente AG, Winterthur, Switzerland b Product Manager - SBF Road & Traffic, Kistler Instrumente AG, Winterthur, Switzerland c Consultant, Corner Stone International Sagl.,Claro, Switzerland Abstract This paper makes an assessment of the ways that Weigh-In-Motion (WIM) systems are used in the different ways of tolling. The main characteristics, advantages and challenges of three tolling methods will be discussed; direct tolling by vehicle class, direct tolling by weight and indirect tolling. The specifics of using WIM systems for the different tolling applications both in low speed (toll plazas) and in high speed (free flow) conditions - is described though a number of recent projects including the difference in operational conditions, requirements and restrictions. The paper concludes with a summary of the main characteristics of the various ways of tolling, will describe the recent developments and finally expected trends for the future. Keywords: Tolling, Road vehicles, Weigh-In-Motion, WIM Résumé Ce document fait une évaluation de la façon dont les systèmes de pesage en mouvement (WIM) sont utilisés dans les différents moyens de péage. Les principales caractéristiques, avantages et défis de trois méthodes de péage seront discutés; péage direct par catégorie de véhicule, péage direct en fonction du poids et péage indirect. Les détails concernant l utilisation de WIM pour différents types de péage - à la fois en basse vitesse (des gares de péage) et à pleine vitesse (flux libre) sont décrits à travers un certain nombre de projets récents, comprenant différentes conditions d'exploitation, d exigences et de restrictions. Le document se termine par un résumé des principales caractéristiques des différents moyens de péage, et décrira les développements récents et les futures évolutions auxquelles on peut s attendre. Mots-clés: péage, véhicules routiers, pesage en marche, WIM a David Cornu, tel: +41 52-224 1429, fax: +41 52-224 1414, E-mail address: david.cornu@kistler.com b Christoph Gilgen, tel: +41 52-224 1585 fax: +41 52-224 1414, E-mail address: christoph.gilgen@kistler.com c Hans van Loo, tel: +41 79 936 0706, E-mail address: hans.vanloo.int@gmail.com
1. Introduction 1.1. Toll roads Toll roads can be found in many countries around the world, with a share varying from a few per cent to 100% of the countries expressway network. Even countries without toll roads often do have tolls for specific bridges or tunnels. Toll roads may be operated by government agencies or private companies. The purpose of toll generally is to generate revenues dedicated to the construction and maintenance of that specific road or parts of the road network. In some cases toll fees are used for user related payment, to internalise the negative effects of road usage (e.g. heavy vehicle tax or congestion related prices) or to finance regional development policies. The objective for a toll road will affect both the level of toll and the period of tolling. Where toll fees only are intended to cover construction costs, and the traffic levels are high, then toll fees will only be required for a relatively short period, e.g. for bridges or tunnels. In other cases the toll will have a more permanent character. A few examples of short term toll to cover building costs from the Netherlands are: the 1 st Benelux-tunnel in the highway A-4 under the Nieuwe Maas river near Rotterdam were toll was collected from 1967 until 1980, the Zeeland-bridge in the provincial road N-256 over the Oosterschelde in the province Zeeland with toll between 1965 until 1993 and the Wijker-tunnel in the highway A-9 under the North Sea channel near Amsterdam with shadow toll for 30 years after construction in 1996. 1.2. Toll variations and options Typically the amount of toll is related to the distance travelled along the road and the type - or characteristics - of the vehicle. However other options are possible, (Worldbank 2001): Cost of road construction, the cost of road construction through specific difficult areas, e.g. longer tunnels through mountains or long bridges over water, are likely to cost more to construct than those across flat open landscapes justifying higher toll rates; Variation by time of day and/or day of the week. This is typically used in order to reduce the effects of congestion, and may be combined with waived for high occupancy vehicles; Social considerations. Some countries make political decisions to encourage certain developments in transportation, e.g. by promoting the usage of high occupancy vehicles and public transport; Tolling by area. In cities like Singapore and London have an area pricing scheme to reduce congestion specifically in the city centre; Vignette system, used in some European countries where the vignette holder has access to all roads within a particular geographic area, as necessary during a specified period. These tolls are less directly related to use of the road. Therefore frequent users are paying less per trip than infrequent users. In this paper three basic options to collect toll fees are distinguished, even though combinations of the mentioned options are possible: Manual tolling, where the toll is paid at a toll both either in cash or by credit card. This is still the most common method of tolling since it does not require advanced technology. Nevertheless it is a slow system because each vehicle has to stop and pay its fee, this may cause severe traffic disruptions and requires more toll booths/lanes than any other to be able to process the same traffic flow. Electronic, where all users are required to carry tags in their vehicles and the toll is deducted from the account connected to the tag. Here the tolling procedure is much faster since users can pass the toll gates at normal or slightly reduced highway speeds, but without stopping. As a result less traffic lanes are required for the process and the traffic flow is not disrupted; Shadow toll, here a private consortium of companies is responsible for the financing, design, building, operation of the toll road. After completion of the road the consortium is paid by the government based on the availability and/or usage of the road, for example the number of vehicles that pass a section of the road.
1.3. Issues One of the problems in the raising of revenue is that the traffic and toll levels may not be sufficient to cover all costs, including construction, operation and maintenance. Especially in developing countries where traffic levels are still low or where construction costs are high, it is unlikely that the toll fee will ever cover more than operation and maintenance and perhaps a part of the construction cost. At the same time overloading by heavy goods vehicles will result in increased damage to the roads, pavements and bridges. This will result in additional maintenance and a reduction of the overall lifespan of the road. This means that the operational costs are increased and at the same time the period of recovering the construction costs is reduced. 2. Tolling using WIM 2.1. Weigh-In-Motion A Weigh-In-Motion (WIM) system is defined as the combination of all hardware (weighing-sensors, induction loops, sometimes digital cameras and computer equipment for data processing) that is installed in, under, over and next to the road. Any WIM system measures, calculates and stores several data items of all passing vehicles (trucks) related to: The vehicle that passed, this consists of the wheel loads and axle loads, gross vehicle weight, axle distances, number of axles and vehicle classification. The passage of the vehicle, consisting of the date, time, lane, direction and speed of the passage. Over the last decades different manufactures of WIM systems have used various different sensor technologies for their systems. For example bending plates, load cells, bridge WIM, piezo-ceramic, piezo-polymer and piezoquartz. Each of these have they own specific characteristics and (dis-)advantages, (Jacob, 2010). Kistler s Lineas WIM sensors based on piezo-quartz technology are characterised by a high measurement accuracy, a long term stability and a quick installation in different types of road pavements. Fig. 1. Lineas weigh-in-motion sensor. Independent of the technology that is used WIM systems have been used for many years for a number of different applications: Pavement loading, this is the original application of WIM. Here the data is used to generate statistical overviews of the distribution of axle loads and weights of passing trucks. This information is used for the design of new and the maintenance planning of existing road pavements and bridges;
Overload enforcement, when combined with digital cameras WIM system become a powerful tool in the selection and enforcement of overloaded trucks. In this case the WIM data is used on a vehicle by vehicle base, requiring more accurate and reliable measurements. In case the WIM measurements are used directly for enforcement of the overloaded trucks even stricter requirements apply on the accuracy and reliability of each individual measurement; Tolling, this is a relatively new application of WIM technology. In this case the WIM system is ether used to determine the height of the toll of each individual vehicle or the fee for the overall usage of the road over a certain period of time. 2.2. Traffic loading An essential element in the design, maintenance and operational life of roads and bridges is the actual traffic load over time; the number, weights and axle loads of all passing vehicles. In case of road pavements because of the exponential relation - generally a 4 th power is used higher axle loads cause a disproportional amount of damage. For damage to bridges the total vehicle weights are more relevant, combined with the number of vehicles and the distances between vehicles. The actual traffic loading has a direct impact on the life expectancy of the road and the amount of maintenance required keeping it up to the required standard. For example; over the 20 years period the effects of serious overloading may result in 3 times repaving instead of the planned 2 times. Only a WIM system is capable of measuring the actual traffic load. 2.3. Overload enforcement There are different ways how WIM systems can be used to increase the efficiency of the enforcement of overloading. First a WIM system can be used to determine peaks in overloading by location, by time of day, day of the week and type of vehicle. This can be used to optimise the planning of weight controls and results in a more efficient deployment of enforcement recourses. Second and probably most common when used as a pre-selection tool a WIM system will give an indication of probably overloaded vehicles. This will increase the hit-rate of actually overloaded trucks to more than 95%, resulting in more efficient weight controls and reduce the number of correctly loaded vehicles that are stopped. Third, in case of company profiling the WIM system is operational 24/7, all passing trucks are controlled and the overloaded trucks are recorded. Using the licence plate of the recorded trucks the owner can be found, the enforcement officers can focus their attention only on inspections of the most overloaded companies. Ultimately WIM systems can be used for direct enforcement, where the penalty for overloading is directly based on the measurement by the WIM without any secondary measurement. This type of enforcement if highly efficient since all passing vehicles are controlled and the enforcement process can be fully automated. However this application requires highly accurate and reliable WIM systems that have been approved by metrology and legally as measurement equipment for enforcement. 2.4. Applications of WIM for tolling WIM systems can be used in different ways to improve the efficiency of existing tolling procedures and allows new more advanced ways of tolling. The main advantage of low speed WIM over static scales for manual tolling is the improved efficiency through a higher throughput and less disturbances to the traffic flow. A low speed WIM system automatically determines the vehicle length, class, weight and the individual axle loads as the vehicle passes over. Most toll operations have fees that are based on vehicle type, where the vehicle type is related to the number of axles and the higher the number of axles, the higher the fee will be. This type of tolling will in fact encourage overloading of axle loads, since vehicles transporting a certain load with fewer axles and causing more damage through higher axle loads will pay a lower fee than a vehicle that has more axles. The use of WIM allows the calculation of a fee that is related to the actual axle loads and thus to the actual consumption of the road when the vehicle uses it. This way tolling by weight acts as a natural incentive to reduce overloading, unlike other ways of tolling that sometimes even promote overloading. Tolling by weight also allows for a special added fee in case of overloading or even refuse access to the toll road for overloaded vehicles altogether. Reduced overloading will result in lower damages to the road pavements and bridges and consequently in lower maintenance costs.
3. Examples of the use of WIM for tolling 3.1. Tolling by weight in China Recent years have seen a large number of new toll roads as part of the Chinese highway network. Many of these toll roads use a tolling scheme based on the actual weight of the passing vehicles. For this slow speed Weigh-In- Motion systems are used, per lane the installation typically consists of, (see figure 2): WIM sensors for weight measurements, two rows of 2 Lineas sensors in a standard layout or two rows of 1 Lineas sensors in staggered layout; IR light curtain for vehicle classification and separation; Tyre detector, sensor for single/double wheel detection (optional); Cabinet containing the electronic equipment for data processing. Fig. 2. A typical tolling by weight installation. In China these systems are tested, approved and certified by the Regional laboratories of the Chinese National Legal Metrological Verification Institute according to the international OIML R-134-1 (OIML, 2006) standard specifications and test procedures. These specifications apply only to WIM systems which are installed in a controlled weighing area where the speed of the measured vehicles is controlled, in other words low-speed (LS) WIM systems. The standard specifies different accuracy classes for measurement of the gross vehicle weight and for the axle loads. The type of system described above has been certified for measuring axle loads up to 30 tons with a maximum permissible error of 2,5% during the initial verification. This means that it has been approved for measuring class 5 during operation. 3.2. Swiss Heavy Vehicle Fee (LSVA) At the moment the Swiss Weigh-In-Motion network consists of 9 locations spread over the Swiss highway network covering the main transport routes. At each location two WIM systems are measuring the truck traffic, one in each direction. The systems consist of two rows of Kistler Lineas Piezo Quartz sensors and two induction loops per lane. The owner and main user of the systems is ASTRA (the Swiss Ministry of Transport) who use the data for statistics on traffic loading for road design and planning of maintenance purposes. The systems have been operational for up to 15 years, they are calibrated annually and generally perform according to COST-323 class B(10). Recently the EZV (the Swiss Customs Administration) has become interested in the WIM measurements as a means for additional verification of their LSVA program. The LSVA is the Swiss performance related heavy vehicle fee. The height of the fee depends on the total permissible weight and emissions level of the vehicle combined with the kilometres the vehicle has driven in Switzerland and Liechtenstein. The fee is levied on all
motor vehicles and trailers that have a total permissible loaded weight of more than 3.5 tons that are used to transport goods and are driven on the Swiss public road network. Vehicles registered in Switzerland must be equipped with an on-board recording device, which determines the exact mileage based on the signal transmitted by the tachometer. Drivers of foreign vehicles not fitted with a recording device must register the relevant details concerning their vehicle the first time they cross the border. From then on, each time the vehicle enters Switzerland the driver goes to a clearance terminal at the border to enter the actual mileage and the presence of a trailer. When exiting Switzerland the LSVA-fee is then calculated based on the difference between entrance-mileage and exit-mileage combined with the characteristics of the vehicle. Fig. 3. A permanent Swiss LSVA control system. The Customs Administration checks the proper LSVA-declaration with fixed and mobile monitoring points. Currently 25 fixed LSVA-monitoring installations on the Swiss motorway network are in operation, see figure 3. These installations identify all passing trucks by means of automatic number plate recognition for foreign trucks and via a DSRC radio link with the on-board unit for Swiss vehicles. The data gathered by all the fixed and mobile monitoring points is collected in a central data base where it is further processed and analysed. In case an infringement is detected the owner of the vehicle involved will be penalised. Based on the results of the Footprint project (Poulikakos, 2009) the Swiss Customs Administration started to upgrade some of their LSVA monitoring installations with WIM-sensors. The WIM measurements are combined with the standard LSVA-data (vehicle ID, vehicle length, date and time of passage). In this way it is possible to check the registered maximum weight with the actual weight of the vehicle when passing the site. This offers a powerful additional means of control for the Swiss Customs. For the truck drivers, both Swiss and foreign, the addition with WIM does not change anything in the declaration or payment procedure, unless they drive overloaded of course. 3.3. DBFMO-contracts in the Netherlands In recent years the first DBFMO (Design, Build, Finance, Maintain and Operate) contracts have been awarded for two sections of the Dutch highway network by Rijkswaterstaat (Dutch Ministry of Transport). The first is a section of the A-12 highway between the cities of Utrecht and Veenendaal in the centre of the country awarded to the Poort van Bunnik consortium. The second section (see figure 4) is the connection of the highway A-15 in the harbour of Rotterdam to connect the Vaanplein with the newly build addition to the harbour (the second Maasvlakte) awarded to the A-lanes consortium. In both cases the contract concerns approximately 35km of highway, starting with the renovation of the existing roads, bridges and noise barriers and afterwards the maintenance/operation period of 20 years. Special attention is paid to maximize the availability of the roads and to minimize the disturbance of the traffic flow and the impact on the environment (noise, vibrations, etc.). These elements are incorporated into criteria to evaluate the
performance of the contractors, which in turn is used as basis for the payments and penalties - by Rijkswaterstaat. The operational phase of the section of the A-12 started recently in March 2013, for the A-15 the completion of the renovation phase and the start of the operational phase is planned for the end of 2015. The renovation phase for the A-15 is longer because of the complexity of the road network, high traffic volumes and the situation inside the area of the busiest harbour of Europe. A15 Maasvlakte Rotterdam A15 A15 Vaanplein Fig. 4. Highway section A-15; Maasvlakte Vaanplein. At the moment both the design and the planning of the maintenance is based on information from the standard WIM-NL network of Rijkswaterstaat. This network was initiated about 15 years ago and currently consists of 20 WIM installations covering the main highway network in the Netherlands. The data is collected in a central data base and is used by Rijkswaterstaat for statistics on traffic loading for the design and maintenance planning of road pavements and bridges. The WIM-network is also used by the IL&T (Environment and Transport Inspectorate) for the enforcement of overloading by heavy goods vehicles. The WIM systems are used as a preselection tool for road side controls and for company profiling to target bad transport companies. The statistical data from this standard WIM network is used as a reference for the traffic loading on the section of road in the DBFMO-contract. The development (growth) of the truck traffic over the 20 years operational period is estimated based on economic and traffic models. Disadvantages of this approach are: The WIM-data is not taken from the actual road section of the DBFMO contract concerned. Traffic flows, traffic loading and overloading may vary considerably from one highway to the next. This means that the damage to the road pavements and bridges over the 20 years may be considerably higher than expected. This in turn will result is a serious increase of the maintenance costs involved, e.g. instead of the 2 times repaving planned during 20 years it may be required to have the pavement replaced 3 times. Especially in case of the A-15 highway directly from the harbour of Rotterdam the number of heavy trucks will be considerably higher than on the rest of the Dutch highway network. This will result in higher maintenance costs for the contractors. On the other hand the example of the Wijker-tunnel has shown that over the first 15 years of the contract Rijkswaterstaat has paid 386 million in shadow tolls, (Eikelenboom, 2013). This is almost the double of the amount invested by the contractors at the start of the project ( 185 million). The reason is that the shadow toll is based on the number of passing vehicles, which has proved much higher than expected. Second the number of passing vehicles has no direct relation with the consumption of the tunnel ; The WIM-data is provided by Rijkswaterstaat. As one of the parties in the contract the WIM-data may not be accepted by the contractor in case of a conflict. Because of the amounts of money involved in these contracts, the costs and penalties for additional road works these conflict are better avoided. The future will show if this approach is sufficient to avoid conflicts over the costs of additional maintenance because of overloading.
A more secure approach to avoid future problems would be to have dedicated WIM systems installed in each direction on the road sections concerned from the start of the maintenance period, furthermore, to have a certified independent third party to provide WIM data with a guaranteed minimum quality as basis for the calculation of the possible additional maintenance costs. All it takes is an investment of less than 0,5 of the overall budget for the contract (±1,5 billion). 4. Conclusions Toll roads, tunnels and bridges have been around for ages and can be found all around the world. The objective is always to generate revenues, the way these revenues are used and the basis for calculation of the toll fees may vary from one road to the next. Weigh-In-Motion systems offer a number of applications for more advanced ways of tolling based on the actual weight and axle loads of the passing vehicles. Over the years Kistler has provided WIM sensors and systems for various tolling operations, used for different applications, operated under a range of conditions all over the world. As shown by the examples for manual toll collection in China, electronic tolling in Switzerland and a possible shadow toll in the Netherlands. 5. References Eikelenboom, S., Kakebeeke, P., Koot, J., Banken verdienen fors aan Wijkertunnel, Financieel Dagblad, 10-5- 2013, in Dutch; Jacob, B., Feypell-de la Beaumelle, V.,(2010). Improving truck safety: Potential of weigh-in-motion technology, IATSS Research 34 (2010) 9-15, Elsevier Ltd; OIML R 134-1, (2006), International Recommendation, Automatic insturments for weighing road vehicles in motion and measuring axle loads, part 1 Metrological and technical requirements Tests, International Organisation of Legal Metrology; Poulikakos L.D., Lees A.R. Heutschi K., Anderegg P., Comparisons of the environmental footprint of heavy vehicles, Transportation Research Journal, issue 7, October 2009, ISSN 1361 9209; Wordbank (2001), Toll Roads and Concessions, www.worldbank.org/transport/roads/toll_rds.htm.