News & Publications


Backseat Drivers are more helpful than you think 

Having a passenger in the car can make a trip safer and more enjoyable, compared to driving alone, according to research by University of Waikato psychology professors Samuel Charlton and Nicola Starkey.

TRG academics promote Transport Futures

Professors Barry Barton and Mark Apperley featured in a panel discussing the future of transport, as part of the University's "Imagine Sustainability" day on campus. This event is about the society, the economy, and the environment we live in, and will provide a platform for staff, students, businesses and the wider community to discuss and work together on sustainability issues. The day included presentations, networking sessions, workshops, research showcases, displays, entertainment, and an Eco My Flat competition.

Electric car star hits the road to Waikato campus

An international electric car superstar, electric vehicle owners, enthusiasts, and researchers came to the University of Waikato in a bid to help encourage uptake of electric vehicles (EVs).

One of New Zealand’s leading energy, natural resources and environmental law specialists Professor Barry Barton says a number of perceptual factors contribute to consumer uncertainly and doubt about electric vehicles, and the ‘Leading the Charge’ road trip is a spectacular way to address those issues and improve perceptions of electric vehicles.

“However, research also indicates that in addition to consumer awareness, Government policies need to be reviewed to encourage the use of electric vehicles in New Zealand, particularly when transport is a rapidly growing contributor to New Zealand’s greenhouse gas emissions.”

Motorists distracted by speedo?

An overly strict focus by the police on speeding leaves motorists focussed on their speedos and not the road, the Police Minister has told Parliament. Associate Professor Samuel Charlton of Waikato University, a specialist in driver behaviour, said it was an interesting idea but he was not aware of any research in this area.

He said it was more usual to find that drivers did not know what speed they were going at. "Far more often, they are not sure what speed they are going, and they aren't really sure in urban areas what the speed limit is. So that's probably a bigger issue than worrying about staying within a one or two kilometre an hour tolerance of the speed limit."

Electric Vehicles: Promoting Improvements in Transport

Electric vehicles are attracting a lot of interest as a desirable alternative to conventional internal combustion vehicles. What adjustments can we make to legal and policy settings to encourage their entry into the New Zealand vehicle fleet? This article draws on a growing base of international research about policies in different countries for electric vehicles (EVs, ie passenger on-road cars that derive all or some of their power from the electricity grid). It shows that EV policy cannot be made in isolation from policy concerning the internal combustion engine vehicles (ICVs) of the conventional vehicle fleet.

Speed and risk on urban roads (funded by New Zealand Automobile Association Research Foundation)

Drivers’ speed choice is known to be influenced by some kind of subjective road categorisation, but the road features that characterise different categories remain unknown. In this study, 55 participants chose a speed for a variety of roads by driving videos in simulation; completed a picture sort task with photos of the roads they had just driven; and answered a series of questions about each road. Participants indicated what speed they would drive each road, the safe speed, and their speed limit belief; and provided subjective ratings of comfort, difficulty and familiarity.

Overall, drivers’ categorisation of roads was informed by a number of factors including speed limit belief, road features and markings (including medians), road width, and presence of houses, driveways and footpaths. The participants’ categories matched what they thought the speed limits were, but these did not necessarily match the actual speed limit for each road. Participants’ beliefs about speed limits were primarily based on what they thought the speed limit was on that type of road, even though they had just viewed and driven the roads (which including the posted speed limits) in the video. The findings provided insights into how drivers view and categorise roads, and identify specific areas that could be used to improve speed limit credibility.

Drivers’ mental representations of rural roads (funded by the Faculty of Arts and Social Sciences, University of Waikato)

The purpose of this research was to understand whether drivers categorise different types of rural road according to the types of driving the different roads require. The research method was a picture sorting task for 34 rural road scenes. Participants rated the roads individually in terms of their speed, difficulty, comfort and safety.

Drivers’ judgments were analysed and six distinct rural road categories were defined. Drivers had significantly different judgments about speed, difficulty, comfort and safety for roads in each of the different categories. The results showed that drivers have underlying mental representations of roads, which influence aspects of their driving behaviour as well as subjective feelings of comfort and safety.

The close to home effect in road crashes

We have all heard that crashes are more likely close to home, but there had been no research to find out whether this was simply a matter of a high amount of travel on roads close to where drivers live. This study was a comparison of travel and crash data from New Zealand databases, representative of all travel and crashes over 12 months from July 2013 to June 2014.

Results showed a close to home effect exists for drivers of cars and vans: injury crashes are over-represented on roads within 10km of a driver’s home. These roads accounted for 57% of crashes but only 46% of travel. The effect held for all except novice drivers (with a learner licence) who had a higher proportion of travel than crashes on roads close to home.

The effect may be related to complacency on familiar roads, given that restraints and alcohol were more likely to be a factor in crashes close to home.  It is recommended that more consideration is given by policy-makers to risks inherent on familiar, urban roads.

Watch: Newshub "Nearly all drivers daydream behind the wheel"

Drugged driving in New Zealand (funded by New Zealand Transport Agency)

Compared with research into drink driving, the prevalence of driving under the influence of legal and illegal drugs is not well understood. This study addressed a gap through telephone and web surveys of over 2,000 New Zealand drivers.

Participants were asked to report their use of various legal and illegal drugs, including whether they had consumed these drugs within three hours of driving. The most common drugs consumed prior to driving were alcohol (13% of the sample), strong painkillers (11%), anti-depressants (7%) and other medication.

The most concerning finding was that many people combined alcohol with other drugs before driving. Combining these substances leads to relatively high driving impairment and crash risk. It is recommended that efforts are made to communicate risks to drivers, particularly the combination of legal drug use with alcohol.

Watch: One News "'Significant problem' - new study suggests drug driving risk eludes many kiwis"

Driving with ADHD

This research investigated the on-road driving performance of individuals with ADHD across a range of road and traffic conditions to determine whether errors were linked to situational complexity and attentional demands.

The everyday driving performance of medicated drivers with ADHD, unmedicated drivers with ADHD, and controls was tested in urban, residential, rural, and highway environments. Unmedicated drivers with ADHD displayed fewer safe driving skills and committed more inattentive and impatient driving errors, particularly in low demand highway and rural driving conditions. Medicated drivers’ performance was not reliably different than controls. Participants in both ADHD groups were more likely than controls to report risky driving and involvement in crashes.

The results show that situations with low attentional demand are particularly risky for unmedicated ADHD drivers and suggest that focus on these situations may be useful in improving safety for this population.


Charlton, S. G., & Starkey, N. J. (2020). Co-driving: Passenger actions and distractions. Accident Analysis & Prevention144, 105624. doi:10.1016/j.aap.2020.105624

Lehtonen, E., Malhotra, N., Starkey, N. J., & Charlton, S. G. (2020). Speedometer monitoring when driving with a speed warning system. European Transport Research Review12(1). doi:10.1186/s12544-020-00408-8

Sivasubramaniyam, R. D., Charlton, S. G., & Sargisson, R. J. (2020). Mode choice and mode commitment in commuters. Travel Behaviour and Society19, 20-32. doi:10.1016/j.tbs.2019.10.007 Open Access version:

Starkey, N. J., Charlton, S. G., Malhotra, N., & Lehtonen, E. (2020). Drivers’ response to speed warnings provided by a smart phone app. Transportation Research Part C: Emerging Technologies110, 209-221. doi:10.1016/j.trc.2019.11.020 Open Access version:

Sivasubramaniyam, R., Sargisson, R., & Charlton, S. G. (2020). Satisfaction from satisficing: Understanding commuters' satisficing tendencies. Transportation Research Interdisciplinary Perspectives6, 100158. doi:10.1016/j.trip.2020.100158

Richards, D. S., & Charlton, S. G. (2020). Forgotten or never consciously processed? A comparison of immediate and delayed recall of driving details. Transportation Research Interdisciplinary Perspectives6, 100149. doi:10.1016/j.trip.2020.100149

Thomas, F. M. F., & Charlton, S. G. (2020). Inattentional blindness and information relevance of variable message signs. Accident Analysis and Prevention140. doi:10.1016/j.aap.2020.105511

Starkey, N., & Charlton, S. (2020). The New Zealand public’s readiness for connected- and autonomous-vehicles (including driverless), car and ridesharing schemes and the social impacts of these. Wellington: New Zealand Transport Agency Research Report 663..

Wang, Y., Jia, S., Zhou, H., Charlton, S., & Hazen, B. (2020). Factors affecting orderly parking of dockless shared bicycles: an exploratory study. International Journal of Logistics Research and Applications, 1-23. doi:10.1080/13675567.2020.1727424

Starkey, N. J., & Charlton, S. G. (2020). The role of control in risk perception on rural roads. Accident Analysis & Prevention142, 105573. doi:10.1016/j.aap.2020.105573

Dua, M. J., & Charlton, S. G. (2019). Audio on the go: The effect of audio cues on memory in driving. Transportation Research Interdisciplinary Perspectives1, 100004. doi:10.1016/j.trip.2019.100004

Burdett, B. R. D., Charlton, S. G., & Starkey, N. J. (2019). Mind wandering during everyday driving: An on-road study. Accident Analysis and Prevention122, 76-84. doi:10.1016/j.aap.2018.10.001

Charlton, S. G., Starkey, N. J., & Malhotra, N. (2018). Using road markings as a continuous cue for speed choice. Accident Analysis and Prevention117, 288-297. doi:10.1016/j.aap.2018.04.029

Charlton, S. G., & Starkey, N. J. (2018). Transitions within a safe road system. Accident Analysis & Prevention121, 250-257. doi:10.1016/j.aap.2018.09.022

Charlton, S. G., & Starkey, N. J. (2018). Memory for everyday driving. Transportation Research Part F: Traffic Psychology and Behaviour57, 129-138. doi:10.1016/j.trf.2017.06.007

Burdett, B. R. D., Charlton, S. G., & Starkey, N. J. (2018). Inside the commuting driver's wandering mind. Transportation Research Part F: Traffic Psychology and Behaviour57, 59-74. doi:10.1016/j.trf.2017.11.002

Malhotra, N., Charlton, S., Starkey, N., & Masters, R. (2018). Examining ironic processes in tourist drivers: Driving on the unfamiliar side of the road. Safety4(3), 1-13. doi:10.3390/safety4030028

Malhotra, N., Charlton, S. G., Starkey, N. J., & Masters, R. (2018). Driving speed choice: The role of conscious monitoring and control (reinvestment) when driving. Transportation Research Part F: Traffic Psychology and Behaviour57, 115-128. doi:10.1016/j.trf.2017.06.006

Burdett, B. R. D., Starkey, N. J., & Charlton, S. G. (2018). Characteristics of the close to home crash. Safety Science105, 222-227. doi:10.1016/j.ssci.2018.02.020

Charlton, S. G., & Starkey, N. J. (2018). (Editorial) Attention and awareness in everyday driving. Transportation Research Part F: Traffic Psychology and Behaviour57, 1-3. doi:10.1016/j.trf.2018.04.014

Burdett, B. R. D., Starkey, N. J., & Charlton, S. G. (2017). The close to home effect in road crashes. Safety Science98, 1-8. doi:10.1016/j.ssci.2017.04.009

Starkey, N. J., Charlton, S. G., Malhotra, N., & Ameratunga, S. (2017). Prevalence of psychotropic drug use prior to driving. Journal of Transport & Health4, 108-117. doi:10.1016/j.jth.2016.12.004

Malhotra, N., Starkey, N. J., & Charlton, S. G. (2017). Driving under the influence of drugs: Perceptions and attitudes of New Zealand drivers. Accident Analysis and Prevention106, 44-52. doi:10.1016/j.aap.2017.05.011

Charlton, S. G., & Starkey, N. J. (2017). Driving on urban roads: How we come to expect the ‘correct’ speed. Accident Analysis and Prevention108, 251-260. doi:10.1016/j.aap.2017.09.010

Charlton, S. G., & Starkey, N. J. (2017). Drivers' mental representations of familiar rural roads. Journal of Environmental Psychology50, 1-8. doi:10.1016/j.jenvp.2017.01.003

Starkey, N. J., & Isler, R. B. (2016). The role of executive function, personality and attitudes to risks in explaining self-reported driving behaviour in adolescent and adult male drivers. Transportation Research Part F: Traffic Psychology and Behaviour38, 127-136. doi:10.1016/j.trf.2016.01.013

Charlton, S. G., & Starkey, N. J. (2016). Risk in our midst: Centrelines, perceived risk, and speed choice. Accident Analysis and Prevention95, 192-201. doi:10.1016/j.aap.2016.07.019

Burdett, B. R. D., Charlton, S. G., & Starkey, N. J. (2016). Not all minds wander equally: The influence of traits, states and road environment factors on self-reported mind wandering during everyday driving. Accident Analysis and Prevention95, 1-7. doi:10.1016/j.aap.2016.06.012

Randell, N. J. S., Charlton, S. G., & Starkey, N. J. (2016). Driving With ADHD: Performance effects and environment demand in traffic. Journal of Attention Disorders-online, 1-11. doi:10.1177/1087054716658126

Ahie, L. M., Charlton, S. G., & Starkey, N. J. (2015). The role of preference in speed choice. Transportation Research Part F: Traffic Psychology and Behaviour30, 66-73. doi:10.1016/j.trf.2015.02.007

Charlton, S. G., & Starkey, N. J. (2015). Driving while drinking: Performance impairments resulting from social drinking. Accident Analysis and Prevention74, 210-217. doi:10.1016/j.aap.2014.11.001

Charlton, S. G., Starkey, N. J., Perrone, J. A., & Isler, R. B. (2014). What’s the risk? A comparison of actual and perceived driving risk. Transportation Research Part F: Traffic Psychology and Behaviour25, 50-64. doi:10.1016/j.trf.2014.05.003

Starkey, N. J., & Charlton, S. G. (2014). The effects of moderate alcohol concentrations on driving and cognitive performance during ascending and descending blood alcohol concentrations. Human Psychopharmacology29(4), 370-383. doi:10.1002/hup.2415

Wilson, N., Thomson, G., Starkey, N. J., & Charlton, S. G. (2013). Persisting mobile phone use while driving and possible solutions for New Zealand. The New Zealand Medical Journal126(1384), 138-140. Retrieved from

Charlton, S. G., & Starkey, N. J. (2013). Driving on familiar roads: Automaticity and inattention blindness. Transportation Research Part F: Traffic Psychology and Behaviour19, 121-133. doi:10.1016/j.trf.2013.03.008

Isler, R. B., Starkey, N. J., & Sheppard, P. (2011). Effects of higher-order driving skill training on young, inexperienced drivers' on-road driving performance. Accident Analysis and Prevention43, 1818-1827. doi:10.1016/j.aap.2011.04.017

Charlton, S. G., & Starkey, N. J. (2011). Driving without awareness: The effects of practice and automaticity on attention and driving. Transportation Research Part F14(6), 456-471. doi:10.1016/j.trf.2011.04.010

Isler, R. B., & Starkey, N. J. (2010). Evaluation of a sudden brake warning system: Effect on the response time of the following driver. Applied Ergonomics41(4), 569-576. doi:10.1016/j.apergo.2009.12.002

Isler, R. B., Starkey, N. J., & Williamson, A. R. (2009). Video-based road commentary training improves hazard perception of young drivers in a dual task. Accident Analysis and Prevention41(3), 445-452. doi:10.1016/j.aap.2008.12.016

Harms, IM, Burdett, BRD, Charlton, SG (2021). The role of route familiarity in traffic participants’ behaviour and transport psychology research: A systematic review. Transportation Research Interdisciplinary Perspectives.

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