Bicyclists‘ speed adaptation strategies when conducting self-paced vs. system-paced smartphone tasks in traffic

Publisher's full text
Lisa Palmqvist
Emeli Adell

The increasing prevalence of mobile phone usage while cycling has raised concerns, even though the number of cyclists involved in accidents does not increase at a comparable rate. A reason for this may be how cyclists adapt travelling speed and task execution to the current traffic situation. The aim of this study is to investigate speed adaptation among cyclists when conducting self-paced (initiated by the cyclist) vs. system-paced (initiated by somebody else) smartphone tasks in real traffic. Twenty-two cyclists completed a track in real traffic while listening to music, receiving and making calls, receiving and sending text messages, and searching for information on the internet. The route and the types of tasks were controlled, but the cyclists could choose rather freely when and where along the route to carry out the tasks, thus providing semi-naturalistic data on compensatory behaviour. The results clearly show that cyclists use conscious strategies to adapt their speed to accommodate the execution of secondary phone tasks. Regarding tactical behaviour, it was found that cyclists kept on cycling in 80% of the system-paced cases and in 70% of the self-paced cases. In the remaining cases, the cyclists chose to execute the phone task while standing still or when walking. Compared to the baseline (17.6 ± 3.5 km/h), the mean speed was slightly increased when the cyclists listened to music (18.2 ± 3.7 km/h) and clearly decreased when they interacted with the phone (13.0 ± 5.0 km/h). The speed reduction profile differed between self-paced and system-paced tasks with a preparatory speed reduction before task initiation for self-paced tasks. In conclusion, when the cyclists had the chance they either stopped or adapted their speed proactively to accommodate the execution of the phone task. For self-paced tasks, the speed reduction was finalised before task initialisation, and for system-paced tasks the speed adaptation occurred in reaction to the incoming task. It is recommended to investigate whether the observed compensatory behaviour is enough to offset the possible negative effects of smartphone use.



Shipping and the environment – research meets reality

Centre for Transport Studies (CTS) in co-operation with Ports of Stockholm invite you to the seminar Shipping and the environment – research meets reality.



Simulation of cut-in by manually driven vehicles in platooning scenarios

A study in a VTI-driving simulator has showed that a platoon will be able to handle a cut in from a manually driven car. The results of this study have recently been presented at two conferences in Japan.



The five-year anniversary of European Road Profile Users' Group (ERPUG) Forum will take place at Ramboll head quarter, Copenhagen, Denmark October 19-20, 2017.


Self-driving buses in Sweden next year?

A self-driving, fossil-free bus. This idea might become reality through a forthcoming collaborative project involving the Swedish National Road and Transport Research Institute (VTI), Linköping University and several other participants. The project group aim...


New climate-proof solutions for hard surfaces in cities

High-density road infrastructure that emphasise maximum durability and minimum maintenance create inflexible systems, which put increased stress on urban trees and lead to increased risk for flooding. Over the past five years, the ‘Climate-proof solutions for...


VTI is preparing for automated vehicles

Automation of traffic systems will lead to major changes. The European Union’s (EU) CoEXist research project began in June 2017 with the aim of preparing cities and road operators for the introduction of self-driving vehicles. The Swedish National Road and...


Vehicle Driver Monitoring: sleepiness and cognitive load

To prevent road crashes it is important to understand driver related contributing factors, which have been suggested to be the critical reason in 94 per cent of crashes. The overall aim of the project Vehicle Driver Monitoring has been to advance the...