Modeling adaptive reversible lanes: A cellular automata approach
PLOS ONE
RESEARCH ARTICLE
Modeling adaptive reversible lanes: A cellular
automata approach
Dante Pérez-Méndez ID1,2*, Carlos Gershenson ID1,2,3, Marı́a Elena Lárraga4, José
L. Mateos2,5
1 Instituto de Investigaciones en Matemáticas Aplicadas y en Sistemas, Universidad Nacional Autónoma de
México, Ciudad de México, México, 2 Centro de Ciencias de la Complejidad, Universidad Nacional Autónoma
de México, Ciudad de México, México, 3 Lakeside Labs GmbH, Klagenfurt am, Wörthersee, Austria,
4 Instituto de Ingenierı́a, Universidad Nacional Autónoma de México, Ciudad de México, México, 5 Instituto
de Fı́sica, Universidad Nacional Autónoma de México, Ciudad de México, México
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OPEN ACCESS
Citation: Pérez-Méndez D, Gershenson C, Lárraga
ME, Mateos JL (2021) Modeling adaptive
reversible lanes: A cellular automata approach.
PLoS ONE 16(1): e0244326. https://doi.org/
10.1371/journal.pone.0244326
Editor: Feng Chen, Tongii University, CHINA
Received: September 4, 2020
Accepted: December 7, 2020
Published: January 4, 2021
Copyright: © 2021 Pérez-Méndez et al. This is an
open access article distributed under the terms of
the Creative Commons Attribution License, which
permits unrestricted use, distribution, and
reproduction in any medium, provided the original
author and source are credited.
Data Availability Statement: The data underlying
the results presented in the study are available
from Transport Infrastructure Ireland at https://
web.nra.ie/CurrentTrafficCounterData/index.html.
Funding: This paper was support by Consejo
Nacional de Ciencia y Tecnologı́a, México, http://
www.conacyt.gob.mx, grant number 630617,
recipient D.P., PAPIIT UNAM(IN116220), recipient
J.L.M., PAPIIT UNAM(IN107919) and PAPIIT
UNAM(IV100120), recipient C.G. No additional
external funding was received for this study. The
funders had no role in study design, data collection
*
Abstract
Dealing with traffic congestion is one of the most pressing challenges for cities. Transport
authorities have implemented several strategies to reduce traffic jams with varying degrees
of success. The use of reversible lanes is a common approach to improve traffic congestion
during rush hours. A reversible lane can change its direction during a time interval to the
more congested direction. This strategy can improve traffic congestion in specific scenarios.
Most reversible lanes in urban roads are fixed in time and number; however, traffic patterns
in cities are highly variable and unpredictable due to this phenomenon’s complex nature.
Therefore, reversible lanes may not improve traffic flow under certain circumstances; moreover, they could worsen it because of traffic fluctuations. In this paper, we use cellular
automata to model adaptive reversible lanes(aka dynamic reversible lanes). Adaptive
reversible lanes can change their direction using real-time information to respond to traffic
demand fluctuations. Using real traffic data, our model shows that adaptive reversible lanes
can improve traffic flow up to 40% compared to conventional reversible lanes. Our results
show that there are significant fluctuations in traffic flow even during rush hours, and thus cities would benefit from implementing adaptive reversible lanes.
Introduction
One of the major challenges in modern cities is to reduce traffic congestion [1, 2]. Improving
public transport and promoting the use of alternative vehicles such as bikes and scooters is
critical to reducing the number of cars on the streets. In addition to the above mentioned, we
can also improve traffic congestion by implementing smart routing strategies, smart traffic
lights, or changes in the infrastructure, such as reversible lanes. Far from conflicting, these
strategies are complementary to improve traffic congestion. In the 1920s, some cities in the
United States started to implement reversible lanes to deal with increasing traffic [3]. The
reversible lane approach lies in this assumption: During rush hours, traffic flow in some twoway streets increases in one direction with respect to the other direction. In most cities, it is
PLOS ONE | https://doi.org/10.1371/journal.pone.0244326 January 4, 2021
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and analysis, decision to publish, or preparation of
the manuscript.
Competing interests: The authors have declared
that no competing interests exist.
Modeling adaptive reversible lanes: A cellular automata approach
expected that early in the morning, people living in the suburbs commute to their workplaces
in the center of the city and return home in the afternoon. This behavior creates an asymmetric
demand in the roads that connect the city’s border with the center. Using this insight, city
planners can decide to change a lane to a more demanding direction in a specific time interval
[4]. As a result, the road’s capacity is increased in the direction with more traffic flow but
reduced in the opposite direction. The reversible lanes are an easy way to increase road capacity without adding new infrastructure. However, they require exceptional planning and operation to have adequate performance.
The existing methods for setting up a reversible lane are based in the observation that in
most cases, there are two distinct peaks on the traffic demand, one in the morning and one in
the afternoon. Based on these patterns, traffic managers decide to change the reversible lanes’
direction for a fixed time [5]. It could be one or several hours, depending on the duration of
the rush hour [6]. When the traffic behaves as expected, the reversible lanes perform effectively. However, traffic in a big city is just a part of a complex system; numerous components
and their interactions determine traffic flow patterns [7]. As a consequence, traffic congestion
is a highly unpredictable phenomenon. It is hard to predict the traffic flow fluctuations at short
time scales because it could be affected by an accident, a closed street, or faulty traffic lights
kilometers away. We are now aware that reversible lanes cannot operate optimally because
of these traffic flow fluctuations. We can even think of extreme scenarios where the traffic
demand is the opposite of the expected one, resulting in a worse performance than the situation without any reversible lane.
Since the beginning of 2020, many urban areas worldwide have experienced massive mobility changes due to the COVID-19 pandemic. The restrictions imposed by governments and
the disease itself have shaped how we move in the city [8]. Alternative transport modes, such
as bikes and scooters, have more demand than before the pandemic. In contrast, public transport systems, such as the metro and bus, are in much lower demand because people are trying
to avoid crowded environments. Similarly, we can expect an increase in the number of people
who prefer to use a particular vehicle due to the worry of becoming infected. Once the pandemic is over, there is a (...truncated)