A paradox of traffic and extra cars in a city as a collective behaviour

Abstract

Promoting walking or cycling and reducing cars’ use is one of the city planners’ main targets, contributing to a sustainable transport method. Yet, the number of vehicles worldwide is increasing as fast as the population, and motorized mobility has become the primary transport method in most cities. Here, we consider modal share as an emergent behaviour of personal decisions. All individuals minimize their commuting time and reach an equilibrium under which no person is willing to change their transportation mode. In terms of the minimum travel time, the best-case scenario is used to determine the extra commuting time and the excess cars, computed as a social inefficiency. Results show that commuting times could increase up to 25% with many more vehicles than optimum. Paradoxically, all individuals trying to minimize their time could collectively reach the maximum commuting times in the extreme case, with all individuals driving during rush hour.

Correlates of Active Commuting to School among Portuguese Adolescents: An Ecological Model Approach

“…These results are similar to those of another study [ 18 ], which showed that participants with higher family incomes and education reported a lower prevalence of AC. This is mainly due the fact that the paradox of traffic [ 51 ] and an increase in the purchasing power of families foment the purchase of motorized vehicles, which are used to transport young people in their daily routines. The importance of the economic question can also be extrapolated to the national dimension.…”

Growing urban bicycle networks

“…In any case, resistance to such ideas needs to be anticipated 5 , 70 , requiring vigorous policy making and a well-informed civil society following leading examples such as the Netherlands 11 , 52 . Sustainability science provides overwhelming evidence for the societal benefits of following such persistent implementations, facilitating the transition to cities with sustainable transport systems to counteract climate change effectively, and providing extraordinary benefits to public health and urban livability 2 , 9 , 18 , 19 , 67 , 75 .…”

Urban Mobility

“…Further, cars come with massive inefficiencies due to their skewed space requirements and usage patterns [81]. Apart from empirical evidence that this is unsustainable [82], also mathematical models from complexity science show that cities as (car-centric) transport monocultures are not sustainable [83,84], and that a mere replacement of fossil fuel cars with electric vehicles is not an adequate solution [85,86,87,88], especially when time-tested, much more efficient and economic, solutions such as mass transit or bicycles are available.…”