Shaping urban traffic patterns through congestion charging : What factors drive success or failure?

Congestion costs are emerging as one of the most important challenges faced by metropolitan planners and transport authorities in first world economies. In US these costs were as high as 78 million dollars in 2005 and are growing due to fast increases in travel delays. In order to solve the current and severe levels of congestion the US department of transportation have recently started a program to initiate congestion pricing in five metropolitan areas. In this context it is important to determine those factors helping its implementation and success, but also the problems or difficulties associated with charging projects. In this article we analyze worldwide experiences with urban road charging in order to extract interesting and helpful lessons for policy makers engaged in congestion pricing projects and for those interested in the introduction of traffic management tools to regulate the entrance to big cities.

Motorways, tolls and road safety. Evidence from European Panel Data

The use of tolls is being widespread around the world. Its ability to fund infrastructure projects and to solve budget constraints have been the main rationale behind its renewed interest. However, less attention has been payed to the safety effects derived from this policy in a moment of increasing concern on road fatalities. Pricing best infrastructures shifts some drivers onto worse alternative roads usually not prepared to receive high traffic in comparable safety standards. In this paper we provide evidence of the existence of this perverse consequence by using an international European panel in a two way fixed effects estimation.

Experimental analysis of optimization techniques on the road passenger transportation problem

Analyzing the state of the art in a given field in order to tackle a new problem is always a mandatory task. Literature provides surveys based on summaries of previous studies, which are often based on theoretical descriptions of the methods. An engineer, however, requires some evidence from experimental evaluations in order to make the appropriate decision when selecting a technique for a problem. This is what we have done in this paper: experimentally analyzed a set of representative state-of-the-art techniques in the problem we are dealing with, namely, the road passenger transportation problem. This is an optimization problem in which drivers should be assigned to transport services, fulfilling some constraints and minimizing some function cost. The experimental results have provided us with good knowledge of the properties of several methods, such as modeling expressiveness, anytime behavior, computational time, memory requirements, parameters, and free downloadable tools. Based on our experience, we are able to choose a technique to solve our problem. We hope that this analysis is also helpful for other engineers facing a similar problem

Cargo Traffic on the Helsinki-Tallinn Route

The twin-city model has found to increase economical activity and well-being. The similar economical, social and cultural background of Finland and Estonia as well as the EU integration give good preconditions to create a twin-city of Helsinki and Tallinn. The relatively long distance between Helsinki and Tallinn is challenging. Therefore, good transport infrastructure and functioning connections are required to form a twin-city of Helsinki and Tallinn. The connections between these cities can be considered also in broader perspective than only from the viewpoint of the twin-city concept. New markets areas have been emerged in Europe due to collapse of planned economy and integration of Europe. Also the transport routes to the markets are changing. The Hel-sinki-Tallinn sea route can be considered as a fast route to the new markets in the Cen-tral and Eastern Europe. The Helsinki-Tallinn sea route is also a potential route to the Western European markets. This study provides an analysis of transport and cargo flows between Finland and Esto-nia for regional and local planners. The main purpose of the study is to clarify the pre-sent situation of the seaborne cargo flows on the Helsinki-Tallinn route and how the cargo flows will develop in the future. The study focuses on the following thematic enti-ties: the Finnish and Estonian seaborne transport system and cargo flows, the structure and volume of the cargo flows on the Helsinki-Tallinn route, the hinterland cargo flows on the Helsinki-Tallinn route and the transport methods used on the Helsinki-Tallinn route. The study was carried out as a desk research, a statistical analysis and an inter-view study during the spring–autumn 2011. The study reveals that during the period 2002–2010 the volume of the seaborne cargo traffic between Finland and Estonia has increased significantly while the trend of the trade volume between Finland and Estonia has remained nearly constant. This indicates that the route via Estonia is increasingly used in the Finnish foreign trade. Because the ports of Helsinki and Tallinn are the main ports in the cargo traffic between Finland and Estonia, the role of the Helsinki-Tallinn route as a sea leg in the hinterland connections of Finland has increased. The growth of the cargo volume on the Helsinki-Tallinn route was estimated to continue on the annual level of 10 % during the next couple of years. In the long run the growth of the cargo volumes depends on the economical and indus-trial development of the former Eastern European countries. If the IMO’s sulphur regu-lations will come in force, the Helsinki-Tallinn route will become one of the main routes also to the Western European markets, besides of the route via Sweden. The study also shows that the fast and reliable connections year round on the Helsinki-Tallinn route have made it possible for service and logistics companies to reconsider their logistics strategies in a new way in the both side of the Gulf of Finland. Anyway, the ropax concept is seen as the only economical profitable solution on the Helsinki-Tallinn route because cargo and passenger traffic are supporting each other. The trucks (vehicle combinations) will remain the main mode of transport on the Helsinki-Tallinn route because general cargo is the main commodity on the route. IMO’s sulphur regula-tions and the changes in the structure of the Finnish industry may create prerequisites for rail road transport in the hinterland connections of Finland. The twin-city model has found to increase economical activity and well-being. The similar economical, social and cultural background of Finland and Estonia as well as the EU integration give good preconditions to create a twin-city of Helsinki and Tallinn. The relatively long distance between Helsinki and Tallinn is challenging. Therefore, good transport infrastructure and functioning connections are required to form a twin-city of Helsinki and Tallinn. The connections between these cities can be considered also in broader perspective than only from the viewpoint of the twin-city concept. New markets areas have been emerged in Europe due to collapse of planned economy and integration of Europe. Also the transport routes to the markets are changing. The Hel-sinki-Tallinn sea route can be considered as a fast route to the new markets in the Cen-tral and Eastern Europe. The Helsinki-Tallinn sea route is also a potential route to the Western European markets. This study provides an analysis of transport and cargo flows between Finland and Esto-nia for regional and local planners. The main purpose of the study is to clarify the pre-sent situation of the seaborne cargo flows on the Helsinki-Tallinn route and how the cargo flows will develop in the future. The study focuses on the following thematic enti-ties: the Finnish and Estonian seaborne transport system and cargo flows, the structure and volume of the cargo flows on the Helsinki-Tallinn route, the hinterland cargo flows on the Helsinki-Tallinn route and the transport methods used on the Helsinki-Tallinn route. The study was carried out as a desk research, a statistical analysis and an inter-view study during the spring–autumn 2011. The study reveals that during the period 2002–2010 the volume of the seaborne cargo traffic between Finland and Estonia has increased significantly while the trend of the trade volume between Finland and Estonia has remained nearly constant. This indicates that the route via Estonia is increasingly used in the Finnish foreign trade. Because the ports of Helsinki and Tallinn are the main ports in the cargo traffic between Finland and Estonia, the role of the Helsinki-Tallinn route as a sea leg in the hinterland connections of Finland has increased. The growth of the cargo volume on the Helsinki-Tallinn route was estimated to continue on the annual level of 10 % during the next couple of years. In the long run the growth of the cargo volumes depends on the economical and indus-trial development of the former Eastern European countries. If the IMO’s sulphur regu-lations will come in force, the Helsinki-Tallinn route will become one of the main routes also to the Western European markets, besides of the route via Sweden. The study also shows that the fast and reliable connections year round on the Helsinki-Tallinn route have made it possible for service and logistics companies to reconsider their logistics strategies in a new way in the both side of the Gulf of Finland. Anyway, the ropax concept is seen as the only economical profitable solution on the Helsinki-Tallinn route because cargo and passenger traffic are supporting each other. The trucks (vehicle combinations) will remain the main mode of transport on the Helsinki-Tallinn route because general cargo is the main commodity on the route. IMO’s sulphur regula-tions and the changes in the structure of the Finnish industry may create prerequisites for rail road transport in the hinterland connections of Finland.

Peltipoliisista hengenpelastajaksi : Automaattisen liikenneturvallisuusvalvonnan tarveselvitys 2011 – 2015

Työssä laadittiin automaattisen liikenneturvallisuusvalvonnan kehittämis- ja investointisuunnitelma vuosille 2011-2015 Varsinais-Suomen ja Satakunnan maantieverkolle. Suunnitelmaan kuului nykyisen toimintamallin ja kehittämistarpeiden arviointi sekä vuosina 2011-2015 toteutettavien automaattivalvontajaksojen ja hankkeiden priorisointi. Lisäksi työssä kuvattiin Ruotsissa käytössä olevaa automaattivalvontatekniikkaa ja -toimintamallia sekä esitettiin toimenpide-ehdotuksia automaattivalvonnan hyväksyttävyyden lisäämiseksi. Nykyistä toimintamallia ja automaattivalvonnan kehittämistarpeita arvioitiin asiantuntijahaastattelujen perusteella. Asiantuntijat pitivät nykyistä toimintamallia pääasiassa toimivana ja tehokkaana, sillä suhteellisen pienillä kustannuksilla on päästy tehokkaisiin tuloksiin. Automaattivalvonnassa on kuitenkin asiantuntijoiden mielestä vielä kehitettävää ja Ruotsin toimintamallia pidettiin hyvänä suuntana ja esimerkkinä. Suurimpina kehittämiskohteina pidettiin tekniikan kehittämistä sekä tiedon käsittelyn nopeuttamista ja automatisointia, mikä lisäisi poliisin resursseja valvonnan suorittamiseen. Vuosina 2011-2015 toteutettavat automaattivalvotut tiejaksot priorisoitiin ensisijaisesti onnettomuustiheyksien, onnettomuusmäärien, Tarva-laskentatulosten, nopeustietojen ja liikennemäärien perusteella. Onnettomuustilastoista huomioitiin lähinnä henkilövahinkoon johtaneet onnettomuudet. Lisäksi Tarva-laskentatuloksia hyödynnettiin automaattivalvonnan vaikutusten ja tehokkuuden arvioinnissa. Haastateltujen asiantuntijoiden mielestä tärkeimmät keinot hyväksyttävyyden lisäämiseksi olivat valvonnan avoimuus, valvontalaitteiden näkyvyys ja jatkuva valvonnasta tiedottaminen. Tiedottamisella tuodaan esille järjestelmän hyödyt ja sen merkitys liikenteelle ja liikenneturvallisuuteen. Myös automaattivalvontakameran brändin muuttamista Ruotsin mallin mukaisesti turvallisuuskameraksi pidettiin hyvänä. Tässä työssä esitettiin suunnitelma automaattivalvonnan hyväksyttävyyden lisäämiseksi.

Valtatie 1 liikenneturvallisuustarkastus : Tarkastusraportti

Tämän työn tavoitteena oli tarkastella liikenneturvallisuuden kehittymistä moottoritien rakentamisen jälkeen valtatiellä 1 Varsinais-Suomen ja Uudenmaan ELY-keskusten alueilla välillä Turku – Lohja. Laadittu tarkastus perustui onnettomuustietoihin, tierekisteritietoihin sekä maastokäynteihin. Valtatien 1 liikenneturvallisuustaso on lähtökohtaisesti hyvä ja liikenneympäristön turvallisuusriskit ovat pienet. Liikenneturvallisuustilanne on parantunut merkittävästi moottoritieksi rakentamisen jälkeen. Valtatiellä 1 tapahtuneet henkilövahinkoon johtaneet onnettomuudet ovat vähentyneet 60 - 80 % moottoritien rakentamisen jälkeen, mikä tarkoittaa lähes 40 henkilövahinko-onnettomuutta vähemmän vuosittain. Kuolemaan johtaneiden onnettomuuksien vähenemä oli 2-3 onnettomuutta vuosittain. Moottoritiellä tapahtuneista henkilövahinkoon johtaneista onnettomuuksista yleisimpiä ovat yksittäisonnettomuudet ja peräänajo-onnettomuudet. Henkilövahinko-onnettomuuksista noin 60 % johtuu tieltä suistumisista. Onnettomuusrekisteritietojen mukaan henkilövahinkoon johtaneita kohtaamisonnettomuuksia ei tapahtunut vuosina 2007– 2011, vaikka väärään suuntaan ajamisesta johtuvat kuolonkolarit on aikaisemmin todettu vakiintuneeksi onnettomuustyypiksi moottoriteillä. Tehdyn onnettomuusanalyysin sekä maastokäyntien perusteella etenkin vanhempien moottoritieosuuksien liikenneturvallisuuden tilaa voidaan ja tulee kuitenkin edelleen parantaa ja liikenneturvallisuustasoa nostaa. Yksittäisonnettomuuksia voidaan estää ja niiden seurauksia merkittävästi lieventää reunaympäristöä kehittämällä. On kuitenkin huomattava, että kaikkia onnettomuuksia ei voida estää tieteknisin keinoin ja liikennejärjestelmää kehittämällä. Maastokäynneillä silmämääräisesti todettuihin puutteisiin pohdittiin parantamistoimenpiteitä Varsinais-Suomen ELY-keskuksen alueelle. Toimenpiteissä erityishuomiota on kiinnitetty tieympäristön törmäysturvallisuuteen ja väärään suuntaan ajamisen riskin estämiseen ramppiliittymissä. Tieympäristön törmäysturvallisuutta on esitetty parannettavaksi pääasiassa puuston raivauksella ja kaiteiden lisäämisellä. Kaiteiden lisäämisen sijasta on mahdollista parantaa törmäysturvallisuutta maatäytöllä niissä kohdissa, jossa ulkoluiska on liian matala kallioleikkauksen kohdalla. Ramppiliittymissä väärään suuntaan ajamisen riskiä pyritään taas estämään mm. lisäämällä kielletyn ajosuunnan liikennemerkkejä.

Från plåtpolis till livräddare : Behovsanalys för automatisk trafiksäkerhetskontroll 2011 – 2015

I det här arbetet utformades en utvecklings- och investeringsplan för automatisk trafiksäkerhetsövervakning för åren 2011-2015 för landsvägsnätet i Egentliga Finland och Satakunta. Planen innehåller analys av den nuvarande verksamhetsmodellen och förslag hur verksamhetsmodellen kunde förbättras samt förslag om vilka vägavsnitt som ska få automatisk övervakning och vilka projekt som ska prioriteras under åren 2011-2015. Vidare beskrivs i planen den automatiska övervakningsteknik och verksamhetsmodell som används i Sverige samt åtgärdsförslag för att öka den automatiska trafikövervakningens acceptans. Den nuvarande verksamhetsmodellen och behovet av att utveckla den automatiska trafikövervakningen har utvärderats på basis av intervjuer med experter. Experterna ansåg att den nuvarande verksamhetsmodellen i huvudsak är funktionell och effektiv, eftersom man med relativt små kostnader har uppnått effektiva resultat. Den automatiska trafikövervakningen måste dock fortfarande utvecklas och Sveriges verksamhetsmodell ansågs vara en bra förebild och ett gott exempel. De viktigaste utvecklingsområdena ansågs vara utveckling av tekniken, snabbare informationsbehandling och automatisering, vilket skulle öka polisens resurser att verkställa övervakningen. Vägavsnitten som ska få automatisk övervakning under åren 2011-2015 prioriterades främst på basis av olycksfrekvens, antal olyckor, Tarva-beräkningsresultat, hastighetsdata och trafikmängder. Av olycksstatistiken har man främst uppmärksammat personskadeolyckor. Tarva-beräkningarna användes också för att utvärdera den automatiska trafikövervakningens inverkan och effektivitet. Enligt de intervjuade experterna är öppenhet kring övervakningen, synlig övervakningsapparatur och kontinuerlig informationsförmedling bland de viktigaste sätten att öka acceptansen. Genom att informera för man fram systemets fördelar och dess betydelse för trafiksäkerheten. Att förändra övervakningskamerans varumärke till säkerhetskamera enligt Sveriges modell ansågs även vara bra. I detta arbete presenteras en plan för att utveckla acceptansen för automatisk trafiksäkerhetsövervakning.

Scenario-based traffic forecasts for the routes between the PENTA ports in 2020

Maritime transport is the foundation for trade in the Baltic Sea area. It represents over 15% of the world’s cargo traffic and it is predicted to increase by over 100% in the future. There are currently over 2,000 ships sailing on the Baltic Sea and both the number and the size of ships have been growing in recent years. Due to the importance of maritime traffic in the Baltic Sea Region, ports have to be ready to face future challenges and adapt to the changing operational environment. The companies within the transportation industry – in this context ports, shipowners and logistics companies – compete continuously and although the number of companies in the business is not particularly substantial because the products offered are very similar, other motives for managing the supply chain arise. The factors creating competitive advantage are often financial and related to cost efficiency, but geographical location, road infrastructure in the hinterland and vessel connections are among the most important factors. The PENTA project focuses on adding openness, transparency and sharing knowledge and information, so that the challenges of the future can be better addressed with regard to cooperation. This report presents three scenario-based traffic forecasts for routes between the PENTA ports in 2020. The chosen methodology is PESTE, in which the focus in on economic factors affecting future traffic flows. The report further analyses the findings and results of the first PENTA WP2 report “Drivers of demand in cargo and passenger traffic between PENTA ports” and utilises the same material, which was obtained through interviews and mail surveys.

Automatic traffic sign inventory- and condition analysis

This thesis researches automatic traffic sign inventory and condition analysis using machine vision and pattern recognition methods. Automatic traffic sign inventory and condition analysis can be used to more efficient road maintenance, improving the maintenance processes, and to enable intelligent driving systems. Automatic traffic sign detection and classification has been researched before from the viewpoint of self-driving vehicles, driver assistance systems, and the use of signs in mapping services. Machine vision based inventory of traffic signs consists of detection, classification, localization, and condition analysis of traffic signs. The produced machine vision system performance is estimated with three datasets, from which two of have been been collected for this thesis. Based on the experiments almost all traffic signs can be detected, classified, and located and their condition analysed. In future, the inventory system performance has to be verified in challenging conditions and the system has to be pilot tested.

Leveiden keskimerkintöjen liikenneturvallisuusvaikutusten arviointi

Tämän raportin tavoitteena oli käsitellä leveiden keskimerkintöjen liikenneturvallisuusvaikutuksia, toteuttaa mielipidekysely kantatie 54 kokeiluosuuden vaikutusalueella sekä esitellä aiemmin tehdyt tutkimukset ja leveiden keskimerkintöjen taustaa. Raportin on laatinut Eino Lahtinen Hämeen ammattikorkeakoulusta opinnäytetyönään. Työn taustateoriaksi syvennyttiin leveiden keskimerkintöjen historiaan Suomessa ja ulkomailla sekä Suomessa tehtyihin tutkimuksiin aiheesta. Suomessa ja ulkomailla on havaittu jo vuosikymmenten ajan korkealuokkaisten teiden liikenneturvallisuuden heikentyneen liikenteen lisääntyessä. Kohtaamis- ja ohitusonnettomuuksien jäljet ovat usein raakaa katseltavaa ja luettavaa. Huoli kohtaamis- ja ohitusonnettomuuksien määristä ja niiden vakavuuksista painostaa etsimään ratkaisuja tämän kaltaisten onnettomuuksien vähentämiseksi. Tästä syystä on 1980-luvulta lähtien aktiivisesti etsitty liikenneturvallisuutta parantavia kustannustehokkaita ratkaisuja. Visuaalisia vaikutuksia arvioidessa havaittiin jo varhain kaistan leveyden visuaalisen kaventamisen johtavan ajonopeuksien laskuun, joka vähentää onnettomuuksia ja niiden vakavuuksia. Yhdeksi ratkaisuksi esitettiin leveää keskimerkintää, josta on ollut erilaisia kokeiluja ulkomailla 1996 ja Suomessa 2009 lähtien. Työn tuloksena voidaan esittää, että leveiden keskimerkintöjen vaikutukset ajokäyttäytymiseen ovat melko vähäiset, sillä lähes puolet kyselyyn vastanneista ei havainnut muutosta omassa tai muiden ajokäyttäytymisessä. Työn perusteella arvioidaan, että leveät keskimerkinnät vähensivät henkilövahinkoon johtaneita ohitus-, kohtaamis- ja vasemmalle suistumisonnettomuuksia 17 – 21 %. Tutkimuksen perusteella voidaan todeta, että leveitä keskimerkintöjä käytettäessä on varmistuttava riittävästä piennarleveydestä (vähintään 1 m). Leveää keskimerkintää voidaan käyttää alueilla, jossa tien päällysteen leveys on vähintään 10 m, KVL vähintään 1500 ajon/vrk ja tiejakson pituus vähintään 10 km. Leveän keskialueen tulisi olla metrin levyinen.

Potentiel d’une approche populationnelle orientée vers la reconfiguration des environnements urbains pour améliorer la sécurité des piétons

INTRODUCTION : En milieu urbain, l’amélioration de la sécurité des piétons pose un défi de santé publique. Pour chaque décès attribuable aux collisions routières, il y a des centaines de personnes blessées et, dans les pays riches, la diminution du nombre annuel de piétons décédés s’expliquerait en partie par la diminution de la marche. Les stratégies préventives prédominantes n’interviennent pas sur le volume de circulation automobile, un facteur pourtant fondamental. De plus, les interventions environnementales pour améliorer la sécurité des infrastructures routières se limitent habituellement aux sites comptant le plus grand nombre de décès ou de blessés. Cette thèse vise à décrire la contribution des volumes de circulation automobile, des pratiques locales de marche et de la géométrie des routes au nombre et à la répartition des piétons blessés en milieu urbain, et d’ainsi établir le potentiel d’une approche populationnelle orientée vers la reconfiguration des environnements urbains pour améliorer la sécurité des piétons. MÉTHODE : Le devis est de type descriptif et transversal. Les principales sources de données sont les registres des services ambulanciers d’Urgences-santé (blessés de la route), l’enquête Origine-Destination (volumes de circulation automobile), la Géobase du réseau routier montréalais (géométrie des routes) et le recensement canadien (pratiques locales de marche, position socioéconomique). Les analyses descriptives comprennent la localisation cartographique (coordonnées x,y) de l’ensemble des sites de collision. Des modèles de régression multi-niveaux nichent les intersections dans les secteurs de recensement et dans les arrondissements. RÉSULTATS : Les analyses descriptives démontrent une grande dispersion des sites de collision au sein des quartiers. Les analyses multivariées démontrent les effets significatifs, indépendants du volume de circulation automobile, de la présence d’artère(s) et d’une quatrième branche aux intersections, ainsi que du volume de marche dans le secteur, sur le nombre de piétons blessés aux intersections. L’analyse multi-niveaux démontre une grande variation spatiale de l’effet du volume de circulation automobile. Les facteurs environnementaux expliquent une part substantielle de la variation spatiale du nombre de blessés et du gradient socioéconomique observé. DISCUSSION : La grande dispersion des sites de collision confirme la pertinence d’une approche ne se limitant pas aux sites comptant le plus grand nombre de blessés. Les résultats suggèrent que des stratégies préventives basées sur des approches environnementales et populationnelle pourraient considérablement réduire le nombre de piétons blessés ainsi que les inégalités observées entre les quartiers.

Management of Public Road Transport System in Trivandrum City

An efficient passenger road transport system is a boon to any city and an inefficient one its bane. Passenger bus transport operation involves various aspects like passenger convenience, profitability of operation and social, technological and environmental factors. The author’s interest in this area was aroused when he conducted a traffic survey of Trivandrum City in 1979. While some studies on the performance of the Kerala State Road Transport Corporation in specific areas like finance, inventory control etc. have already been made, no study has been made from the operational point of view. The study is also the first one of its kind in dealing with the transportation problems for a second order city like Trivandrum. The objective of this research study is to develop a scientific basis for analysing and understanding the various operational aspects of urban bus transport management like assessing travel demand, depot location, fleet allocation, vehicle scheduling, maintenance etc. The operation of public road transportation in Trivandrum City is analysed on the basis of this theoretical background. The studies made have relevance to any medium sized city in India or even abroad. If not properly managed, deterioration of any public utility system is a natural process and it adversely affects the consumers, the economy and the nation. Making any system more efficient requires careful analysis, judicious decision making and proper implementation. It is hoped that this study will throw some light into the various operational aspects of urban passenger road transport management which can be of some help to make it perform more efficiently

Activity patterns of urban red foxes (Vulpes vulpes) reduce the risk of traffic-induced mortality

Traffic collisions can be a major source of mortality in wild populations, and animals may be expected to exhibit behavioral mechanisms that reduce the risk associated with crossing roads. Animals living in urban areas in particular have to negotiate very dense road networks, often with high levels of traffic flow. We examined traffic-related mortality of red foxes (Vulpes vulpes) in the city of Bristol, UK, and the extent to which roads affected fox activity by comparing real and randomly generated patterns of movement. There were significant seasonal differences in the number of traffic-related fox deaths for different age and sex classes; peaks were associated with periods when individuals were likely to be moving through unfamiliar terrain and would have had to cross major roads. Mortality rates per unit road length increased with road magnitude. The number of roads crossed by foxes and the rate at which roads were crossed per hour of activity increased after midnight when traffic flow was lower. Adults and juveniles crossed 17% and 30% fewer roads, respectively, than expected from randomly generated movement. This highly mobile species appeared to reduce the mortality risk of minor category roads by changing its activity patterns, but it remained vulnerable to the effects of larger roads with higher traffic flows during periods associated with extraterritorial movements.

The impact of traffic emissions on atmospheric ozone and OH: results from QUANTIFY

To estimate the impact of emissions by road, aircraft and ship traffic on ozone and OH in the present-day atmosphere six different atmospheric chemistry models have been used. Based on newly developed global emission inventories for road, ship and aircraft emission data sets each model performed sensitivity simulations reducing the emissions of each transport sector by 5%. The model results indicate that on global annual average lower tropospheric ozone responds most sensitive to ship emissions (50.6%±10.9% of the total traffic induced perturbation), followed by road (36.7%±9.3%) and aircraft exhausts (12.7%±2.9%), respectively. In the northern upper troposphere between 200–300 hPa at 30–60° N the maximum impact from road and ship are 93% and 73% of the maximum effect of aircraft, respectively. The latter is 0.185 ppbv for ozone (for the 5% case) or 3.69 ppbv when scaling to 100%. On the global average the impact of road even dominates in the UTLS-region. The sensitivity of ozone formation per NOx molecule emitted is highest for aircraft exhausts. The local maximum effect of the summed traffic emissions on the ozone column predicted by the models is 0.2 DU and occurs over the northern subtropical Atlantic extending to central Europe. Below 800 hPa both ozone and OH respond most sensitively to ship emissions in the marine lower troposphere over the Atlantic. Based on the 5% perturbation the effect on ozone can exceed 0.6% close to the marine surface (global zonal mean) which is 80% of the total traffic induced ozone perturbation. In the southern hemisphere ship emissions contribute relatively strongly to the total ozone perturbation by 60%–80% throughout the year. Methane lifetime changes against OH are affected strongest by ship emissions up to 0.21 (± 0.05)%, followed by road (0.08 (±0.01)%) and air traffic (0.05 (± 0.02)%). Based on the full scale ozone and methane perturbations positive radiative forcings were calculated for road emissions (7.3±6.2 mWm−2) and for aviation (2.9±2.3 mWm−2). Ship induced methane lifetime changes dominate over the ozone forcing and therefore lead to a net negative forcing (−25.5±13.2 mWm−2).

British railways and the challenge from road haulage: 1919-39

Interwar Britain witnessed the rapid rise of road transport as a serious competitor to the railways. This article examines road–rail competition for freight traffic. It demonstrates that, contrary to previous accounts—which have been highly critical of the railway companies—their failure to prevent rapid loss of traffic to the roads was the inevitable consequence of the regulatory framework under which the railways had been returned to private control in 1921. Given the constraints imposed by this framework, price competition with road hauliers would have further depressed railway company profits. Railway policy thus concentrated on pressing for a revision of the legislative framework governing road–rail competition.