National Transport Survey Research Articles

Reporting on human trafficking crimes: a national transportation survey

Reporting on human trafficking crimes: a national transportation survey

How is freight distribution affected by travel time unreliability?

The impact of travel time unreliability on freight transport has been extensively investigated in the last 20 years with the main focus being placed on mode and route choice (and using mostly stated preference data). In contrast, freight distribution has been very rarely examined in the literature. In this paper, we describe a study on how travel time unreliability affects interregional freight distribution using (revealed preference) data from the last national transport survey carried out in Iran (2015). Through this study, conducted using spatial interaction models and linear and geographically-weighted regression approaches, we found that, globally, travel time reliability is approximately as important as average travel time in determining freight distribution flows, but this importance varies widely across regions. We also found that tardy trip reliability measures describe freight distribution patterns more accurately than statistical range measures (coefficient of variation of travel time).

Integration of Different Mobility Behaviors and Intermodal Trips in MATSim

MATSim is an open-source simulation framework for mesoscopic traffic simulations that has gained popularity in recent years. In this paper, we present a MATSim model for the city of Vienna, with a particular emphasis on the intermodal routing framework used to create agent trips, and the development of a utility function to specify different agents’ mode preferences. To create agent activity chains, we use mobility diaries from the national transportation survey in Austria and disaggregate the available geospatial information to best fit the reported travel times. The novelty of the intermodal framework is the ability to create trips that do not consist of only one mode of transportation, but to also include bicycle, car, and demand-responsive transport (e.g., cab, car sharing) trips in combination with public transportation. To represent the different mobility behaviors of agents, we divide the population into groups and assign them different utility functions for transportation modes according to their socio-demographic characteristics. After presenting the validation of the model, we discuss ways to improve the model.

Electrification of personal vehicle travels in cities - Quantifying the public charging demand

Charging electric vehicles is regarded as trivial with chargers installed on private property, which could accommodate the demand of 78% of the Danish cars. Hence, the owners would rarely need to charge outside the household. Car owners in the cities often do not have this option and must rely on the public charging infrastructure. In this work we quantify the need, in terms of energy demand, for public chargers on a national level and in the largest Danish cities as a function of car ownership, driving distance and household parking condition. We assess the potential of destination charging at existing shared parking facilities next to the household and the workplace to reduce the public charging demand to be up to 87%. EVs with 300 km range are able to complete the daily driving distance without range extending charging in 98.4% of the days. The analysis relies on driving and ownership data based on the Danish national transport survey. Further, we identify suitable/optimal locations for the necessary public chargers based on the total amount of parking time spent by a car at different destinations and the duration of a stay. We generalise the relationship between publicly available information such as population density and city size and the parameters that determine the public charging demand. The systematic approach enables others to estimate the demand in time and space for other cities or countries.

Mobility needs, activity patterns and activity flexibility: How subjective and objective constraints influence mode choice

Denmark is one of the world-leading countries in terms of bicycle infrastructure and has a relatively good public transport system. Yet, a large share of commuters in the Greater Copenhagen Area still uses the car on a regular or semi-regular basis, causing severe problems of congestion and pollution. This article seeks to understand to what extent individuals’ perceived mobility necessities (PMN), activity pattern complexity, and temporal, spatial, social, or compulsory constraints in everyday activities inhibit switching from private motorized transport modes to more environmentally friendly modes. We formulate an Integrated Choice and Latent Variable model that accounts for PMN and activity patterns, complexity and constraints. To estimate the model, we used two datasets: the first dataset is the Danish National Transport Survey, which is a large dataset consisting of approximately 150,000 respondents; the second is a small(er) but highly detailed dataset, which contains relevant information regarding activity patterns, constraints and PMN. We found that the more complex the activity patterns are, the higher are both PMN and the probability of selecting car and bike, and this effect is even more evident when individuals are constrained by some activities. Consistently, individuals who perceive high mobility needs are more likely to select car and bike. The result that mobility needs and related constraints increase cycling conflicts with results found in low-cycling countries. Yet, it indicates that the bike can play a similar role as the car when the respective infrastructure is provided. Our results also indicate that structural improvements, such as flexible work and day-care times, day-care service close to the workplace, or escorting services for children are likely to lead to a substantial reduction in the use of the car.

Flying Cars for Green Transportation

Growing urban populations, land space limitations, and high infrastructure development costs present a challenge for the future of ground-based transportation. Flying cars, no longer confined to the realm of fiction, are in active development today and will see commercial deployment throughout the next decade. Recently in Nature Communications, Kasliwal et al. reported an analysis of the potential for flying cars to reduce both the travel time and carbon footprint of personal travel.

GHG emissions in daily travel and long-distance travel in Germany – Social and spatial correlates

There is considerable research on the climate effects of daily travel, including research on the spatio-temporal and socioeconomic impact factors of daily travel and associated climate change effects. However, this is less true with respect to long-distance trips. This paper uses national transport survey data from Germany to point out differences in GHG emissions related to demographic, socioeconomic and spatial characteristics for daily and long-distance travel. Daily travel and long-distance travel are investigated simultaneously and separately using Logit and OLS regressions. The results show that transport-related GHG emissions from long-distance trips and daily trips are affected by sociodemographics in largely the same direction. In contrast, spatial attributes, like municipality size or density grade of the region, show a different picture. Per capita emissions in rural and suburban areas are higher for daily trips, but lower for long-distance trips than emissions caused by urban residents. While we cannot rule out the possibility of residential self-selection, our findings challenge the idea that compact urban development may help reduce CO2 emissions once long-distance trips are taken into account.

Insulin‐treated diabetes: awareness and adherence to driving recommendations

Sir, We read with interest the recent article by Ken Shaw, entitled ‘Safe driving on insulin: improving implementation using new technology in glucose monitoring?’ (Pract Diabetes 2014;31[9]:361). Hypoglycaemia and hypoglycaemia unawareness are well-recognised and serious complications of insulin therapy. Hypoglycaemia has a significant negative impact on cognitive function, working memory, spatial awareness and emotional well-being.1-4 All of these parameters are essential for a safe driving performance. Studies have demonstrated that insulin-induced hypoglycaemia was associated with poor driving performance.5 At present in the UK, drivers with insulin-treated diabetes are issued with one- to three-year Group 1 licences or one-year Group 2 licences. The Driver and Vehicle Licensing Agency (DVLA) has published guidance on driving regulations and requirements, including recommendations for safe driving precaution measures, and sent it to these drivers at the time of their licences’ application and renewal.6 Nevertheless, previous studies have shown that patients’ awareness and adherence to DVLA's rules and regulations were poor.7, 8 We recently conducted a short survey to assess whether patients are aware of and follow the guidance. An anonymous questionnaire was given to all insulin-treated diabetes patients, over a three-month period. Patients were eligible if they: were >18 years old; had diabetes treated with insulin; held a current UK driving licence and had been driving. Temporary insulin users, e.g. women with gestational diabetes treated with insulin, were excluded. Patients were asked to fill in the questionnaire prior to the consultation with health care professionals in order to avoid recall bias. A total of 75 patients agreed to take part in the survey; however, only 61 patients completed the questionnaire. Over half of drivers in our cohort were aged 51 and above and nearly one-third were over 61 years of age. This age distribution reflects the proportion of elderly drivers in the National Transport Survey.9 The elderly driver group may need particular attention since increasing age is one of the risk factors for severe hypoglycaemia and hypoglycaemia unawareness. Seventy percent of the patients had type 1 diabetes, 25% type 2 diabetes and 5% other type of diabetes. Seventy-nine percent of patients said that driving is an essential part of their daily life or occupation; 93% of patients recognised symptoms of hypoglycaemia most of the time; 13% of patients had experienced a hypo (either mild or severe) while driving in the last 12 months. Just over 70% (43/61) always carry blood glucose testing kits while driving; 87% of patients always carry quick-acting carbohydrates in the car. Just under half of the patients (49%) always check their blood glucose level before driving. Just over half of the patients (52%) always take a break from a long journey to check blood glucose. Eleven percent of patients did not know the safe blood glucose level to drive and 7% said they would drive even when their blood glucose level is below 5mmol/L. Two would continue to drive even if they start to feel symptoms of hypoglycaemia or their blood glucose is less than 4mmol/L. Only 23% would wait the recommended 45 minutes before driving again after an episode of hypoglycaemia. Eighty-four percent of patients stated that they had received advice about driving and diabetes from health care professionals. Just over half of the patients thought that they have received comprehensive advice about driving and diabetes. Only 11% of patients would like to get more detailed information about DVLA rules and recommendations. Nearly 90% of patients thought that they already have enough information and did not want to seek more information. Ten out of 61 patients stated that they did not receive any form of education about driving and diabetes. Worryingly, nine of these patients did not want to get more information relating to driving and diabetes. The results of our study mirrored the findings of previous studies.7, 8, 10 In our sample of patients, most of them recalled that they have received some information about driving and diabetes. However, there is still considerable room for improvement in their knowledge and adherence to safety recommendations. Health care professionals should be more proactive: discussion about driving rules and recommendations should form part of the routine clinic encounter. A patient information leaflet is a good way of reinforcing what has been discussed during consultation. The results of this study raise questions about the knowledge of the health care professionals who complete DVLA fitness to drive forms concerning the recommendations for safe driving for people with insulin-treated diabetes. Further studies in this area are warranted. We thank all of the staff at the diabetes clinic in Wrexham Maelor Hospital for their assistance in distributing and collecting the questionnaire. There are no conflicts of interest declared. References are available at www.practicaldiabetes.com.

The influence of weather characteristics variability on individual’s travel mode choice in different seasons and regions in Sweden

This paper investigates the influence of weather on the Swedish people’s mode choice decision in different seasons and regions using a long term series of the Swedish National Transport Survey datasets (NTS) and weather data from the Swedish Meteorological and Hydrological Institute (SMHI). The weather data includes mean of daily temperature, amount of rain precipitation and road surface condition. The daily mean temperature is normalised based on each region and season and classified into five categories as ‘very cold’, ‘cold’, ‘normal’, ‘warm’, and ‘very warm’. This normalisation approach enables us to investigate the impact of individual’s heterogeneity in perceiving regional and seasonal variability of temperature. The impacts of these weather indicators’ variability on individual’s mode choice is investigated with multinomial logit models. The results show that the impacts of weather differ in different seasons and different regions. Pedestrians’ perception of variation of temperature differs between those in the northern Sweden and those in the central and southern Sweden. Such perception also differs in summer and in spring and autumn. Similarly, northern Sweden cyclists are more aware of temperature variation than cyclists in the central and southern Sweden in spring and autumn when temperature changes significantly. The influence of temperature variation on motorised modes also varies among seasons and regions. However, the trend is less straightforward than that on non-motorised modes. The findings highlight the importance to incorporate individual and regional unique anticipation and adaptations behaviours within our policy design and infrastructure management.

OP36 A Cross-Sectional Assessment of the Effect of the Free Older Persons’ Bus Pass On Active Travel and Regular Walking Among Adults ≥60 Years in England Using Data from the National Travel Survey 2005-2008

BackgroundThe benefits of physical activity for all age groups is well-documented and there is increasing interest in the promotion of incidental physical activity, such as active transport, which includes walking,...

Commuting behaviour and urban form: a longitudinal study of a polycentric urban region in Denmark

This paper is an empirical investigation of the relation between urban form and commuting behaviour in a polycentric urban region. It explores to what extent urban form and location variables help to explain commuting time, distance and mode based on an empirical case, East Jutland, which is a polycentric urban region in Denmark. Data from the National Transport Survey of Denmark were used for this quantitative analysis and two time periods were selected to highlight any potential changes over time. Empirical findings indicate that urban form and location variables help to explain the three selected aspects of commuting. However, urban form variables have greater explanatory power in explaining commuting modes than commuting time and commuting distance. No general trends in commuting were detectable from the data. Finally, the empirical findings revealed specificities of the case study. For instance, two of the important findings are that the distance to the closest urban centre is an important factor which affects the three selected aspects of commuting, while the distance from the residence to the closest large city (i.e. second-ranked city) is associated with a relatively short commuting distance in East Jutland.

Passenger transport and CO 2 emissions: What does the French transport survey tell us?

The aim of this article is to analyse CO 2 emissions caused by passenger transport in France: which socio-demographic groups travel, for what kinds of journey (local or long distance), how and why? Research focusing on the analysis of individual travel can improve the understanding of CO 2 emissions by identifying upstream socio-economic factors, and also enable a better assessment of the potential social impact of measures introduced to limit greenhouse gases due to transport. Calculations are based on the latest French national transport survey (1994). Distances covered and CO 2 emissions were estimated for each journey and for each surveyed individual. A socio-demographic characteristic typology was built and results were obtained through this analysis. If equity and accessibility issues are to be taken into account, planned policies cannot be of the same type if linked to mobility segments. An environmental tax system to limit CO 2 emission increases appears appropriate for long-distance trips. Results are more varied for local journeys, which are often more of a necessity. Nevertheless, income brackets, and measures concerning urban planning or the growth of new car fleets, seem more pertinent.

Equilibrium holdings distributions in durable asset markets

The stock of durable goods can be represented by its holdings distribution, defined as the joint distribution of age and physical condition of the population of durable goods. This paper derives the holdings distribution which arises under stationary conditions when durable goods deteriorate according to a Markov process. We show that given the scrappage and utilization decisions of consumers, the holdings distribution F( x) is an equilibrium distribution of an associated regenerative Markov process. Using a basic result from the theory of regenerative stochastic processes, we characterize F( x) as the ratio of the expected number of periods the durable's condition is better than x to the expected lifetime of the asset. Using data from the 1977 National Transportation Survey we illustrate these results by estimating a simple two-parameter model of automobile deterioration and comparing the implied distribution of automobile holdings to the actual distribution.

Test of a Hierarchical Model of Auto Choice on Data from the National Transportation Survey

In this study a hierarchical decision model of the choice of different size cars is tested and used to make aggregate forecasts of the U.S. automobile market. The model, originally developed in a study of southern California automobile buyers, was tested using two types of national data. First, it was used to predict choices made by the new car buyers who were respondents in the National Transportation Survey done in 1978. Second, an aggregation procedure was developed to enable the model to forecast market shares for different size cars for the period 1980-1990. The predictions of the model were then compared with the actual market shares. Both tests confirm the principal prediction of the model: that there is a constant demand for cars with larger interior capacity. The model answers an important question in transportation policy: what array of fuel- efficient cars will best meet the transportation needs of U.S. families? The aggregation technique developed for the study is a straightforward method for ...