German Motorways Research Articles

Non-driving-related tasks during level 3 automated driving phases–measuring what users will be likely to do.

After activation of a Society of Automotive Engineers (SAE) Level 3 automated driving function (SAE International, 2021), the function takes over the driving task and the human user may engage in other, non-driving-related tasks (NDRTs). Meanwhile, the user needs to remain receptive to requests by the function because s/he needs to reengage in the driving task, when the function approaches a system limit and requests the user to take over. Hence, the effects of NDRT engagement on driver state and takeover behavior have been investigated closely. However, concerning relevance to traffic safety, it is important to take a step back and investigate what NDRTs users are likely to engage in, and what methods are suitable to collect respective data. Two experiments were conducted to answer these questions. In Experiment 1, participants experienced Level 3 automated driving in a Wizard-of-Oz vehicle on German motorways. After the ride, participants were asked to name NDRTs that they would engage in, if the function was available in their own vehicle. In Experiment 2, participants were asked to bring their own NDRTs along and experienced Level 3 automated driving in the Wizard-of-Oz vehicle. Comparison of results shows preferences of similar NDRTs (e.g., smartphone usage and reading). Moreover, we found that different methods provide different insights into NDRT engagement (i.e., engagement rate, total duration rate of engagement, and naming rate). Integrating our results in current literature landscape highlights the strong dependence of resulting NDRTs from the investigation method. Results, strengths, and weaknesses of the employed methods are discussed.

Tourist information boards on motorways: perceptions, memory effects and decision-making support

In recent years more and more tourist information boards have been put up on German motorways. Little research exists with regard to the effects of these information boards. A qualitative research approach was used and 29 semi-structured interviews were conducted to increase knowledge about the relationships between tourist information boards and related tourism behaviour. A model was developed which integrates the elements perception of tourist motorway signage, its memory effects and tourism decision-making processes. Findings suggest that spontaneous driving off the motorway is rarely found and points of interest are more likely to be visited after the trip or used as travel inspiration. This study shows for the first time that tourist information boards can play an important role in tourism decision-making processes and resulting behaviours.

A Duration Approach for Estimating the Marginal Renewal Cost at German Motorways

We estimate the marginal costs of road renewals as part of a social marginal cost scheme for road user charging. Within an analytical approach that mirrors the relationship between road deterioration, traffic load and road renewal, we use an accelerated failure time model for road pavement with the purpose to derive the effect from traffic increase on the length of road renewal cycles. Based on a comprehensive dataset for German motorways we fit a Weibull duration model with covariates such as traffic load from heavy vehicles as well as various control variables and derive the road deterioration elasticity with respect to heavy traffic. Similar to available studies for Sweden we find a deterioration elasticity below one, implying that Newbery’s (1985) fundamental theorem does not hold for the German motorway network. The shape parameter of the Weibull function indicates that there is an ageing or weathering effect, and higher traffic loads are not the sole factor impacting on shorter pavement lifetimes. Our estimations yield a marginal renewal cost, which makes up approximately 40% of the average renewal cost. It implies that road user charges based on marginal costs will not yield a sufficient revenue to cover total costs.

A planning strategy considering multiple factors for electric vehicle charging stations along German motorways

An electric vehicle (EV) charging station planning strategy, considering the construction cost and drivers’ satisfaction, is proposed in this paper. All German motorway pathways and an hourly based resolution traffic flows are collected, and the existing service areas on motorways are presented as potential locations for charging infrastructure. Close service areas are clustered and the optimal positions of charging stations are calculated for each cluster. The charging station construction cost, EV drivers waiting cost as well as the EV inconvenient driving cost are defined. By considering the different types of cost mentioned above synthetically, a planning method that can satisfy the charging demand while reducing the construction cost is proposed. In addition, three different planning scenarios to meet different planning requirements have been proposed. The established optimization problem is a mixed-integer non-linear (MINLP) problem and an improved approach based on genetic algorithm is proposed to solve this problem. Results verify the efficacy of the proposed method.

Quantifying Vision Zero: Crash avoidance in rural and motorway accident scenarios by combination of ACC, AEB, and LKS projected to German accident occurrence

Objective: The Vision Zero initiative pursues the goal of eliminating all traffic fatalities and severe injuries. Today’s advanced driver assistance systems (ADAS) are an important part of the strategy toward Vision Zero. In Germany in 2018 more than 26,000 people were killed or severely injured by traffic accidents on motorways and rural roads due to road accidents. Focusing on collision avoidance, a simulative evaluation can be the key to estimating the performance of state-of-the-art ADAS and identifying resulting potentials for system improvements and future systems.This project deals with the effectiveness assessment of a combination of ADAS for longitudinal and lateral intervention based on German accident data. Considered systems are adaptive cruise control (ACC), autonomous emergency braking (AEB), and lane keeping support (LKS).Methods: As an approach for benefit estimation of ADAS, the method of prospective effectiveness assessment is applied. Using the software rateEFFECT, a closed-loop simulation is performed on accident scenario data from the German In-Depth Accident Study (GIDAS) precrash matrix (PCM). To enable projection of results, the simulative assessment is amended with detailed single case studies of all treated cases without PCM data.Results: Three categories among today’s accidents on German rural roads and motorways are reported in this study: Green, grey, and white spots.Green spots identify accidents that can be avoided by state-of-the-art ADAS ACC, AEB, and LKS. Grey spots contain scenarios that require minor system modifications, such as reducing the activation speed or increasing the steering torque. Scenarios in the white category cannot be addressed by state-of-the-art ADAS. Thus, which situations demand future systems are shown. The proportions of green, grey, and white spots are determined related to the considered data set and projected to the entire GIDAS.Conclusions: This article describes a systematic approach for assessing the effectiveness of ADAS using GIDAS PCM data to be able to project results to Germany. The closed-loop simulation run in rateEFFECT covers ACC, AEB, and LKS as well as relevant sensors for environment recognition and actuators for longitudinal and lateral vehicle control.Identification of green spots evaluates safety benefits of state-of-the-art level 0–2 functions as a baseline for further system improvements to address grey spots. Knowing which accidents could be avoided by standard ADAS helps focus the evolution of future driving functions on white spots and thus aim for Vision Zero.

An Extended Network Interdiction Problem for Optimal Toll Control

We study an extension of the shortest path network interdiction problem and present a novel real-world application in this area. We consider the problem of determining optimal locations for toll control stations on the arcs of a transportation network. We handle the fact that drivers can avoid control stations on parallel secondary roads. The problem is formulated as a mixed integer program and solved using Benders decomposition. We present experimental results for the application of our models to German motorways.

Optimal duty rostering for toll enforcement inspectors

We present the problem of planning mobile tours of inspectors on German motorways to enforce the payment of the toll for heavy good trucks. This is a special type of vehicle routing problem with the objective to conduct as good inspections as possible on the complete network. In addition, we developed a personalized crew rostering model, to schedule the crews of the tours. The planning of daily tours and the rostering are combined in a novel integrated approach and formulated as a complex and large scale Integer Program. The main focus of this paper extends our previous publications on how different requirements for the rostering can be modeled in detail. The second focus is on a bi-criteria analysis of the planning problem to find the balance between the control quality and the roster acceptance. Finally, computational results on real-world instances show the practicability of our method and how different input parameters influence the problem complexity.

Safety of Characteristic Subsections of Roadwork Zones on Motorways

Roadwork zones interrupt the flow of traffic and shall reduce road safety of motorways (autobahns), at least in specific sections. Motorways are the fastest roads in the German roadwork and have the highest level of safety – higher than either roads inside built-up areas or other roads outside built-up areas. Nevertheless, a total of 17,172 accidents involving personal injury occurred on motorways in the year 2011, 1,118 of them at roadwork zones. A total of 18 people were killed and 220 seriously injured. The principal aim of this research project was to find out if either roadwork zones on motorways are more unsafe than other motorways sections or they are specific subsections inside of roadwork zones or near them which are particularly unsafe. The research project consisted of an analysis of the statistics in the vicinity of all roadwork zones on German motorways (autobahns). Road accidents recorded by the police for a period of at least 12 months at 76 selected roadwork zones and a retrospective accident analysis of 12 completed motorway roadwork zones were macroscopic analyzed. In addition, a microscopic analysis of the accident occurrence was carried out of eight existing roadwork zones with a total length of 57 km and included also the analysis of the driving behavior of car and truck drivers throughout the length of the roadwork zones and/or in characteristic subsections in or near them. The results of the research project confirm that accidents at roadwork zones on motorways are generally accidents involving minor damage to property. The accident severity (fatalities per 1,000 accidents involving personal injury) of accidents that occur on sections of motorway without roadwork zones is up to 1.6 times higher than that of accidents that occur at roadwork zones. The study shows different accident rates and accident cost rates for some characteristic subsections along the roadwork site. Nevertheless, there are problem areas in terms of road safety, particularly at the beginning and end of roadwork zones, lane realignment points, carriageway changeover points and temporary slip roads. These characteristic subsections of roadwork zones have an influence on the road safety. The same applies to the impact of how the traffic is routed, the length of the roadwork site or specific road equipment (e.g. road signs against a yellow background).

Influence of Dynamic Traffic Control Systems and Autonomous Driving on Motorway Traffic Flow

As in many other countries, traffic demand on German motorways is continuously rising, especially during peak hours. Enhancing the road infrastructure by building additional lanes or new motorways is cost-intensive and - due to the complex planning process in Germany – extremely tedious. Thus, the government tries to maximise the performance of the existing infrastructure using dynamic control systems. The development and deployment of autonomous driven vehicles can have positive effects on the capacity of road elements. In this study the effect of dynamic control systems on the traffic flow on motorways is analysed in case studies using microscopic traffic simulation. Furthermore it is outlined that autonomous driving in an environment where access to the motorway is limited to autonomous vehicles only can have a positive effect in terms of higher capacities and more harmonized traffic resulting in fewer traffic breakdowns.

Monitoring of Contaminant Input into Roadside Soil from Road Runoff and Airborne Deposition

Non-point sources of traffic-related pollution become a major concern as they – compared to the point-source inputs – are more difficult to be defined or controlled. It is crucial to evaluate the fraction of traffic-related contamination that is transported to the road surroundings as it could negatively impact soil, surface water and groundwater. This study describes two means through which pollutants leave the road to the surrounding environment. Three German motorways were selected (A4, A555, and A61), where runoff and deposits were analyzed to determine pollutant load moving into the roadside soil or into the drainage system. Each of the three motorways carries approximately 70,000 vehicles a day on 4 to 6 driving lanes; and they cover a broad range of truck participation in the total traffic load ranging from 5.4% to 19.8%. The three motorways represent several topographical and landscape features as forest with noise barrier and parallel as well as perpendicular orientation to the main wind direction. Sampling of runoff and deposition was done on monthly basis. Bulk deposition was collected in Bergerhoff vessels at two heights (1.5 m and 0.3 m above the ground) and in 1 m, 2.5 m, 5 m and 10 m distances from the road edge. The results showed that heavy metals as well as large amounts of mineral compounds are moving from the driving lanes into the roadside environment. This includes sodium from applying deicing salts in winter seasons, which could be found in soil, dust and water samples. Calcium and iron were also detected in almost comparable concentrations. The annual deposition flow (bulk deposition) measured at a height of 1.5 m was higher than the comparative values for urban areas and background measuring points. The spatial distribution of material deposition showed clear differences between the three motorways. The pollutant load in deposition measured near the ground surface was higher than those measured at 1.5 m above the land surface. At all three sites, a clear negative correlation between pollutant load and the distance from the roadside could be found. Nearly 90% of the concentration values of heavy metals in road runoff were below or in the range of the test values for seepage water in the German Soil Protection and Contamination Ordinance. The pH-values around 7 in runoff and adjacent soil provide a good retention capacity in the soil for the heavy metal input.

Intelligent Controlled Compact Parking for Modern Parking Management on German Motorways

The high density of commercial freight transport on motorways makes it difficult for truck drivers to find safe parking places especially for longer rest periods during the night. Even though expansions have been made to satisfy the demand in Germany, overcrowding and dangerous situations still occur as a result of vehicles parking on the entrance and exit roads of rest areas. In 2005 a control procedure called “Convoy Parking” was installed at the rest area Montabaur on the A3 motorway in Germany. Convoy Parking is subject to a patent (EP 1 408 455 B1, 2007). Convoy Parking requires all drivers entering their departure time at a terminal in front of a barrier. Subsequently, on the basis of the input data, the automatically detected vehicle length and the actual situation at the rest area, a free parking row is assigned and trucks can be parked sorted. The German Federal Highway Research Institute (BASt) developed a new control procedure called “Intelligent Controlled Compact Parking” (hereafter referred to as “Compact Parking” for short) to achieve that trucks are parking in a compact way, side by side and without a driving lane between trucks. Convoy Parking and Compact Parking have a very different control procedure and appearance. While Convoy Parking assigns a parking row to the driver, Compact Parking deliberately leaves the choice of the parking row to the drivers themselves. Drivers do not have to disclose their departure time to any system and they are not stopped by any barrier because Compact Parking offers a wide range of departure times on variable message signs. Drivers ought to use the parking row where their intended departure time is offered. With the innovative system Compact Parking the capacity of an existing rest area can be quickly increased without enlarging the area. This also avoids long-term planning approval procedures and is friendly to the environment. Besides, the safety for all users of the rest area can be improved by reducing illegal parking. Compact Parking is supported by the German Federal Ministry of Transport and Digital Infrastructure (BMVI). The first installation of Compact Parking is under construction at the rest area Jura-West on the A3 motorway (Northern Bavaria). The Autobahndirektion Nordbayern (Motorway Directorate for Northern Bavaria) is the central agency to plan, build and run the motorways in Northern Bavaria and got the approval of the BMVI to realize the pilot project. BASt accompanies the pilot project and leads the implementation of the control procedure. The opening is scheduled for summer 2015.

Improvement of the volume-delay function by incorporating the impact of trucks on traffic flow

In current transportation modelling, travel time is the most important factor in decisions regarding transport modes, destinations and routes. The calculation of travel time is deployed by volume-delay functions (VDFs), a sub-model of route assignment procedure, using the correlation between increasing numbers of vehicles on a road and the road's restrictive capacity. By investigating existing VDFs, a clear gap is seen, demonstrating that current functions are not suited to reflect the empirically known large impact of trucks on passenger car travel times. This issue becomes crucial when transport models are used to reflect future scenarios where goods transportation is expected to increase greatly, and when transport models combine passenger and commercial traffic. This paper presents a new VDF which successfully includes trucks’ impact on traffic flow in the case of Germany and, with slight deviations, for North America. The function is developed using ideal-type data for German motorways. The differences between German and US data and their implications for VDFs are also discussed.

Germany's National Socialist Transport Policy and the Claim of Modernity: Reality or Fake?

The construction of the extensive motorway network by the Nazi regime has often been seen as a textbook example of a thorough motorisation policy. But the motorway construction took place under a transport policy that favoured public railroads at the expense of private road haulage companies. A strict regulation of freight rates prevented road hauliers from competing with railroads and gaining a greater share of the freight market. The division of administrative and planning competencies between the motor-minded enthusiasts around Hitler's road builder Fritz Todt and the railroad lobby in the Ministry of Transport contributed to a contradictory motorisation policy. Not even the design of the German motorways was favourable to commercial road hauliers. The German Autobahn was built primarily for cars and ignored the needs of the trucking industry.

Optimizing Toll Enforcement in Transportation Networks: a Game-Theoretic Approach

We present a game-theoretic approach to optimize the strategies of toll enforcement on a motorway network. In contrast to previous approaches, we consider a network with an arbitrary topology, and we handle the fact that users may choose their Origin-Destination path; in particular they may take a detour to avoid sections with a high control rate. We show that a Nash equilibrium can be computed with an LP (although the game is not zero-sum), and we give a MIP for the computation of a Stackelberg equilibrium. Experimental results based on an application to the enforcement of a truck toll on German motorways are presented.

In situ measurements of particle number concentration, chemically resolved size distributions and black carbon content of traffic-related emissions on German motorways, rural roads and in city traffic

In-situ measurements of various properties of traffic-related aerosol particles have been performed with a mobile laboratory. The measured aerosol quantities include particle chemical composition (sulfate, nitrate, total organic matter, ammonium, black carbon) as well as particle size distributions covering diameters from 10 to 300nm, and total particle number density. Additionally, gas phase emissions (CO2, NO, NO2) were monitored. We performed six measurement drives in the vicinity of the city of Aachen (population ca. 260,000) at 50.8°N, 6.1°E in Germany on motorways, rural roads, and in the inner city of Aachen in June 2005.The results indicate that the main influence of traffic on the aerosol properties results in soot particles coated with organic matter, having a modal diameter around 100nm (“soot mode”). The abundance of these particles was found to be highest in the inner city traffic. Nucleation mode particles (around 30nm) have been observed occasionally during truck chasings on motorways. These particles consisted mainly of organic compounds but included possibly also a sulfuric acid core. Data observed under “motorway background” conditions were similar to the rural regional road data. Highest number concentrations have been observed during truck chasings. Comparison between non-refractory (here with respect to 600°C) and total particle volume indicated a higher contribution of refractory material under all traffic-influenced conditions compared to rural road data. Fuel specific emission ratios were derived for a subset of 18 truck-chasing experiments, yielding (8.3±5.8)×1015kg−1 for particle number, 224±136mgkg−1 for black carbon, 125±125mgkg−1 for organic matter, 17±12gkg−1 for NO and 18±14gkg−1 for NOx (mean values and standard deviations).

Reactance or acceptance? Reactions towards the introduction of road pricing

We tested the opposite predictions of reactance and dissonance theory, two popular psychological theories, with regard to the responses of car drivers to the introduction of the road pricing. Reactance theory predicts that persons who are convinced that a toll will come are more opposed than less convinced persons. In contrast, dissonance theory expects that convinced persons are more in favour of road pricing than less convinced persons. Aim of the study was to test which theory is more appropriate to explain user reactions towards the toll introduction. We experimentally manipulated the perceived likelihood (low, middle, high and a control condition) of a toll introduction for private cars on German motorways ( N = 140 car drivers). In accordance with the predictions of dissonance theory, results revealed clearly that convinced persons about a definite introduction of road pricing developed more positive attitudes towards road pricing than less convinced persons, i.e., the strength of conviction about the introduction of road pricing has a strong effect on the attitudinal evaluation of road pricing. The implications are discussed.

Strasse, Bahn, Panorama: Verkehrswege und Landschaftsveranderung in Deutschland von 1930 bis 1990 (review)

Reviewed by: Straße, Bahn, Panorama: Verkehrswege und Landschaftsveränderung in Deutschland von 1930 bis 1990 Barbara Schmucki (bio) Straße, Bahn, Panorama: Verkehrswege und Landschaftsveränderung in Deutschland von 1930 bis 1990. By Thomas Zeller. Frankfurt am Main: Campus, 2002. Pp. 451. €45. For a long time transport history was devoted to particular modes and not much concerned with the environmental changes associated with the building of new infrastructure. Neither was transport among environmental history's principal concerns. Now, Thomas Zeller combines both disciplines and integrates them into the history of technology. By concentrating on the relationship between transport and landscape, his book analyzes how motorways and high-speed railways changed the natural environment in Germany. At the same time, he contributes substantially to ongoing debates about the history of German motorways (Autobahn) during the Nazi period. He also develops a new field of research by extending his studies into the period after World War II, concentrating not only on the motorways built in the 1950s and 1960s but also on the new high-speed rail lines of the 1980s. In the first part of his book, Zeller expertly explores "landscape" in its different shapes and meanings. He develops this as an analytic tool through an excellent discussion of the term's various theoretical approaches, drawn from a range of disciplines. In the second part, he goes on to show that although the idea of the Autobahn emerged in the 1920s, it flourished only after the Nazis took over. Landscape architects and road engineers struggled for influence and power, bringing together previously separate dialogues over Autobahn and landscape. "Landscape" was most important for the Autobahn project, because the fusion of the two terms allowed the Nazis to present motorways as a project to enhance the scope and prestige of German technology. In this way the Nazis proposed to modernize both the economy and society while simultaneously avoiding negative side effects. Zeller reveals how different groups of engineers, architects, consultants, conservationists, and politicians shaped the process of integrating the technology of motorways into the landscape without destroying it, keeping landscape's "German" origins. The third part of the book shows how motorways in Germany fundamentally [End Page 215] changed their meaning between 1930 and 1970. After World War II, traffic engineers emphasized mathematical and geometrical methods in an attempt to gain status and demonstrate their modern approach, and to disassociate themselves from "Hitler's roads." Understandably, they avoided mentioning the symbolic significance that motorways had had for the Nazis. Instead, they stressed rational continuity and attacked the concept of roads aesthetically integrated into landscape as a romantic "Sonderweg" (special path). Landscape architects had no influence on the design of roads; they could only plant "greenery" alongside. Motorways should no longer provide panoramic views but function only as efficient facilities for moving traffic. Zeller impressively shows how politicians and other public-interest groups in the 1960s adopted this rhetoric and rejected demands for the naturalistic integration of roads into the landscape, calling this inappropriate to the construction of effective modern roads. This perception only changed in the late 1970s and 1980s, when nature again gained in importance. In the fourth part of his book, Zeller analyzes how the "Shinkansen shock" provoked new plans for high-speed trains in West Germany during the 1960s, though it was only in 1984 that the German Federal Railway decided to build a high-speed network. Rights-of-way were designed by analogy with motorways, where new infrastructure had guaranteed the success of this traffic mode. Interestingly, the minister of transport demanded new lines for both passenger and freight trains, but in the wake of the oil-price crisis plans shrank to a small network for passengers only. In contrast to the example of motorways, civic-action groups heavily criticized the plans for high-speed trains, raising the specter of noise (Verlärmung) and a loss of "Kulturlandschaft." Their protests led to extensive tunneling, deep cuts, and noise barriers—even to route changes. Straße, Bahn, Panorama shows how, between the 1930s and the 1980s, the perception of landscape changed from the ideal of "untouched nature" designed for motorists' enjoyment to developed and cultivated land that...

Neue Wege der Verkehrswegefinanzierung im Spiegel raumordnerischer Ziele und Grundsätze

The first privately operated motorway projects and heavy truck toll collection schemes on German motorways are components of an intensified integration of road usage and financing. Distance-related user charges could entail higher transport costs for peripheral regions. An empirical analysis for Germany reveals that concerning freight transport peripheral regions might be charged twice compared to more central regions, albeit at rather low shares of transport costs in revenues. Concerning car traffic, the urban fringe of agglomerations would bear the highest transport cost increments. Higher transport costs for peripheral regions and, as a consequence, a more compact spatial division of labour might be at odds with the regional equity objective, but would match other objectives of regional planning.

The influence of automobile exhausts on mutagenicity of soils: contamination with, fractionation, separation, and preliminary identification of mutagens in the Salmonella/reversion assay and effects of solvent fractions on the sister-chromatid exchanges in human lymphocyte cultures and in the in vivo mouse bone marrow micronucleus assay

To test the assumption that automobile exhausts contribute to soil mutagenicity, two soils with low levels of mutagenic activities were exposed to traffic exhausts at a heavily charged junction of German motorways (Autobahnen) for 3, 7, 10, 13, 17, 21, and 26 weeks. Indeed, in the presence of a metabolic activation system from rat liver (S9), an average increase of 8 and 9 (4 and 12) revertants per gram per week was found in Salmonella typhimurium TA 98 (TA 100). In the absence of S9, meaningful measurements were impossible on account of a concurrent dose dependent increase of toxicity. No correlation between the increase of mutagenicity and the contents of polycyclic aromatic hydrocarbons (PAH) could be detected. In another series, soils sampled at the roadside and at distances of 10 and 50 m of five roads near Mainz expressed 10–20-fold higher mutagenicity (revertants per gram) under identical test conditions as compared with the average of agricultural soils. Toxic effects, however, again confounded the results and no correlation between the distance from roads and the levels of mutagenicity could be demonstrated. Subsequently, Soxhlet-extraction with the solvent sequence dichloromethane, acetone, and toluene/diethylketone was found to be an optimum procedure for soils at roadsides. The mass balance of solvent fractionation of such soils revealed that <2% each belonged to organic acids and bases, ∼4% to fractions designed polar neutrals, ∼8% to polar aromatics, ∼7% to dichloromethane solubles, and ∼79% to cylohexane solubles, among them ∼63% acetone soluble compounds. The major part of mutagenicity (55–65%) was present in the fraction of polar aromatics, followed by polar neutrals and the acetone subfraction of cyclohexane solubles (∼10% each) summarizing the results obtained with S. typhimurium TA 98, TA 98NR, YG 1021, YG 1024, TA 100, YG 1026, and YG 1029 with and without addition of S9. The modified tester strains, either deficient in nitroreductase (TA 98NR) or overproducing nitroreductase (YG 1021, 1026) or O-acetyl-transferase (YG 1024, 1026), indicated a major contribution of nitroarenes to soil mutagenicity. With respect to mutagenic PAH, high pressure liquid chromatography (HPLC) revealed that >90% of dibenz[a,h]anthracene (4.18 mg/kg soil), benzo[a]pyrene (1.96 mg), benzofluoranthenes (0.14 mg), and benz[a]anthracene (0.18 mg) were present in the acetone subfraction of cyclohexane solubles. Concentrations and mutagenic activities, however, did not correlate. Additional preparative and analytical HPLC of the solvent fractions of polar neutrals and polar aromatics, resulted in the tentative identification of 2-nitrofluorene. Analysis of the vertical profile of soil revealed an increase of mutagenicity per gram from the surface to a maximum at 5–15 cm depth and a subsequent decrease with very little activity remaining deeper than 35 cm. In human lymphocyte cultures, the fraction of polar aromatics, 0.01–0.3 μg/ml, induced 11.27±4.76–20.70±6.19 sister-chromatid exchanges (SCE) per cell in the absence of S9 (solvent control: 10.16±4.83 SCE per cell) and 12.77±6.53–17.87±4.93 SCE per cell in the presence of S9 (solvent control: 8.37±3.92 SCE per cell). However, no activities could be detected in the fractions of polar neutrals and non-polar neutrals. Again, negative results were obtained in the in vivo mouse bone marrow micronucleus assay at 2000 mg/kg p.o. with all fractions.

The effectivity of new traffic‐technologies and transportation‐systems in suburban areas and on motorways

AbstractAt the Forschungsgesellschaft Kraftfahrwesen mbH Aachen (fka) the submicroscopic traffic simulation program PELOPS (Program for the dEvelopment of Longitudinal micrOscopic traffic Processes in a Systemrelevant environment) was developed in co‐operation with the BMW AG. It simulates the traffic flow on motorways with a specific view on vehicle affairs. One application for PELOPS was the assessment of ACC (Adaptive Cruise Control) systems inside the PROMETHEUS program. A new research period extends the use of ACC about the functionality to urban areas. This requires an extension of PELOPS to include some specific models. With this extension, it is possible to analyse new traffic technologies for individual vehicles or infrastructure. Based on detailed traffic measurements, different scenarios are simulated to improve the traffic flow and to relieve the environment. These scenarios include ACC systems, inter‐vehicle‐communication and intelligent traffic lights. Another actual application is the analysis of the influence of new road trains (extra‐long trucks with increased speed and enhanced breaking‐capabilities) on traffic‐flow and driving safety on German motorways. The paper gives detailed information about the simulation techniques and the results of the current analysis.