Use of navigation systems and consequences for travel behaviour
Verena Franken M.A.
German Aerospace Centre (DLR)
within the Helmholtz Community
Institute of Transport Research (IVF)
Rutherfordstrasse 2, 12489 Berlin, Germany
Tel.: +49-30-67055-149, Fax: +49-30-67055-202
E-Mail: [email protected]
Keywords: navigation systems, travel behaviour
Topic: "Intelligent transport systems (ITS)”
Abstract:
On the European market, navigation systems gain growing importance for the support of
travellers on both their everyday and special travels. So they have the possibility to contribute to
the optimization of transport. This assumes that navigation systems are not just a part of the
standard equipment of cars, but have to be used frequently. Therefore a broad acceptance of
navigation systems has to exist. Following a scheme of acceptance which understands acceptance
as a dynamic process the availability and use of navigation systems as well as the influence on
travel behaviour and travellers’ references while using a navigation system are analyzed in this
article.
The report on a study made by DLR-Institute of Transport Research gives an insight about
acceptance and current use of navigation systems. It acts about a nationwide online survey among
1.315 navigation system users, addressing particularly the questions in which situations the
navigation system is utilized, by which frequency and how people use to react to the information
they get.
The author will present the trip purpose specific use of navigation systems, the willingness to
follow recommendations and the influence of travel behaviour by navigation systems. This will
be described as a precondition to deduce potential effects for the German transport system as a
whole in a next step.
1. Introduction
A functioning travel system forms a material prerequisite for the capacity and efficiency of highly
developed societies. Even if stagnant traffic growth has been registered in Germany since 1995,
the development of roadway traffic in the last decade has necessitated the expansion of roadway
infrastructure, which has teetered more and more on the limits of capacity. In this situation, great
expectations are associated with the use of information and communications technologies in the
form of "telematics": a sharp increase in the efficiency of traffic systems through improved use of
existing infrastructure, relief for the environment and an increase in traffic safety.(1) As a
combination of telecommunications and informatics, telematics offers a broad range of
possibilities not only for assisting drivers but also for rendering collective use of transport
infrastructures more efficient.(2) Besides features such as monitoring and positioning,
information and navigation play a prominent role within the recent development of telematics for
individual users.
Travel-related telematic projects both on a national and an international level largely focus on
technical and organizational aspects.(3) Findings concerning the traffic effects of telematics,
particularly the influence on individual travel behaviour, as the basis for potential effects on the
overall system, particularly travel advisory services and navigation, are in contrast only available
to a limited degree. In principle, it is assumed that improved travel information (traffic state,
possible means of transport, etc.) can cause a temporal or geographic intramodal and intermodal
shift.(3) A temporal shift on the part of traffic participants can also lead to relief for the traffic
system, as can a change in the means of travel, for example, from roadway (cars) to rail (light rail
transport). There are knowledge deficits, however, as to whether offers, such as traffic
information services or navigation systems, have an influence on individual travel behaviour and,
if so, on the quantity and quality of these effects. The absence of or only scant empirical
documentation available on the effect of traffic information services and navigation on individual
travel behaviour therefore means that there is no valid empirical evidence to back up the
assumption that traffic information leads to more efficient utilization of traffic infrastructure.
Instead, the effects of an intra- and/or intermodal shift can lead to an increase in the attraction of
congestion-free roads, leading to increased demand for transport. The effects of such a shift might
also be impeded or might cancel each other out, so as to "contribute to an increase in the overall
burden both on infrastructure as well as on people and the environment."(3)
In order to attain initial empirical findings as to the degree to which navigation devices (as a
telematic application that supplies particular information to users) have an influence on individual
travel behaviour, the DLR Institute of Transport Research (IVF) conducted an online survey on
the topic "Acceptance and use of navigation systems." This article provides a brief theoretical
overview of travel behaviour, travel information and acceptance before presenting the survey and
selected results of the study.
2. Theoretical overview
2.1 Travel behaviour and information
Navigation devices aim to provide users information in order to support them in making their
decisions regarding, for example, the shortest or fastest routes.
Considering the effects of navigation systems on individual travel behaviour therefore implies
consideration of decision-making behaviour. On the level of individual travel behaviour, it is
assumed that through the provision of travel information traffic participants rationally weigh all
means of transport and routes against each other and opt, after having weighed the costs and
benefits, for the best route and the most effective means of transport.(4) Rational action, the
centrepiece of economic behaviour theory, assumes full knowledge and foresight of the possible
consequences that could arise from the choice. In order to obtain this knowledge, traffic
participants require the corresponding information which they can receive, in line with the
aforementioned approach, through traffic information services or navigation devices. Yet it must
be noted here that full knowledge and foresight in the spirit of economically motivated, rational
action requires taking a large number of aspects into account (e.g. costs, availability of means of
transport, traffic state, geographic and temporal framework conditions, etc.), so that traffic
information services or navigation devices can in fact tend to improve knowledge. Such services
or devices currently are not be able to take into account all aspects, however, or provide
unrestricted knowledge.
On the other hand, it is generally evident that persons in many situations act as they have acted in
the same or similar situations in the past. Problems first arise when a person is in a situation with
which he or she is unfamiliar and thus does not know how to react.(5) This leads to a real
decision-making situation and is consequently to be differentiated from habitual behaviour.
Various studies (4, 6) show that the choice of the means of transport and/or route more closely
represents habitual behaviour than rational behaviour. Moreover, VERPLANKEN, AARTZ AND VAN
KNIPPENBERG have shown that habitual behaviour carries certain inertia in relation to the choice
of transport. The choice of a means of transport is not always adapted, even in altered situations.
AJZEN'S theory of planned behaviour is for this reason often used to explain travel behaviour. The
theory of planned behaviour assumes "that it is not the objectively given consequences and
restrictions that are relevant to behaviour, but their subjective representations.(7) […] The theory
of planned behaviour also considers the limits of human information processing. It assumes that
people take into account only a few behavioural consequences (normally three to seven) when
making their decisions."(8)
SCHWARZMANN selected his approach to studying the influence of user information systems on
the demand for transport in a similar way. His is also one of the few German articles published on
this subject. SCHWARZMANN assumes that information can be used to influence user demand for
transport as a result of improved knowledge. He assumes in this regard that the "people
demanding transport have incomplete or deficient knowledge about their options for action and
therefore make 'wrong' decisions in the terms of the traffic planner." Options for action can be
rendered more objective and new options for action provided through information.(9) The
implementation of these objectivised or new options for action has a corresponding individual
effect on the demand for transport.
Without going into further detail, this brief overview of relevant theories regarding travel
behaviour and the potential influence of information on decision-making behaviour provides a
basic context.
2.2 User acceptance
In addition to considering decision-making behaviour, aspects related to acceptance must be
taken into account when analyzing the effects of navigation systems on individual travel
behaviour.
User acceptance is a necessary condition for navigation systems to be able to render a
contribution to traffic management. The phenomenon of acceptance is discussed in various fields
of scientific, with varying approaches being pursued.(10, 11) Generally, "acceptance" can be
defined as the positive attitude on the part of a user or decision-maker towards accepting a thing
or situation. This assumes a positive attitude regarding a certain circumstances.(12) The
acceptance process can thus be divided into attitudinal and behavioural acceptance. Emotional
components and components based on experience are combined at the attitudinal level. This
provides the basis for a product or situation being accepted. Behavioural acceptance is displayed
in the form of observable behaviour.(10)
Acceptance can also be construed as the opposite of the term "refusal." In its simplest form, one
can understand acceptance as a yes-no decision. However, this dichotomy is not sufficient for
analyzing the potential support of navigation systems. In addition to the positive acceptance
decision in the form of the purchase of a navigation device, the frequency and intensity of use can
constitute the decisive indicator of acceptance. KOLLMANN (13) assumes in relation to the
acceptance of telecommunications systems that acceptance can be interpreted as a continuum in
the case of usable goods and systems. The switch from a dichotomous form to an acceptance
continuum with due regard to the relevancy of a voluntary decision therefore forms the basis for
KOLLMANN's acceptance model. The latter signifies that the use is voluntary and not determined
by administrative, organizational or policy-related measures, for example. KOLLMANN also
speaks of a usage continuum, which means that a high intensity of use signifies a high degree of
acceptance. Vice versa, this means that a low intensity of use expresses a low degree of
acceptance. This means that the acceptance of navigation systems is expressed, for example,
through the purchase of such a system, which represents a time-related factor. On the other hand,
acceptance is also reflected in intensity of use, which can be subject to temporal changes.
Accordingly, acceptance is a dynamic process. If we follow KOLLMANN, this process is a
multidimensional construct, which is dependent on three levels of explanation. Acceptance is the
general link between an internal assessment and a formed expectation (level of attitudes), an
acquisition or purchase of the product (level of action), and a voluntary, above-average
(measured in terms of the use behaviour of all participants) degree of use (level of use) until the
end of KOLLMANN's entire acceptance process. This also reflects the general distinction between
attitudinal and behavioural acceptance.
An analysis of the entire acceptance process requires different methods according to KOLLMANN.
For example, at the attitudinal level, stated preferences methods are required above all. In
contrast, the level of action can be depicted relatively well through sales and availability figures.
The frequency and intensity of use can in turn provide clues about the acceptance of use. Above
all if we consider the level of use in detail, following questions arise: To what degree are
navigation systems already currently being used? And for what purposes are navigation systems
being used? The answers to these questions provide clues about the influence of navigation
devices on travel behaviour.
3. Survey on acceptance and use of navigation systems
3.1 Underlying database
The following analysis relies on the data from the study performed by the DLR Institute of
Transport Research (IVF) about acceptance and use of navigation systems. This online survey
was held in 2005 by Explanandum, Association for empirical social research, Stuttgart, with a net
sample size of 1,315 persons who own a navigation system. To generate the sample, an address
database from the Schober Information Group was used for the sampling procedure, since in
Germany is no ‘public list’ about persons who possess a navigation device. The Schober
Information Group is able to contact specific target groups by means of their Lifestyle
MarketBase. Twice a year the Schober Information Group performs a consumer survey of
German households. Thus, 5,000 persons who possess navigation devices could be identified and
directly contacted for the IVF online survey. For the reason that detailed information about
navigation system owner are missing, the results can be seen valid only for the respondents of the
survey. As mentioned, the particular objective of the DLR study was to deal with the question of
the contributions navigation systems can make towards the optimization of traffic flows. In light
of this background, the main emphasis was placed on questions about users and the use of
navigation systems. The particular questions I want to discuss here are: For which situations are
navigation systems used? How often are they used? Do users follow the recommendations of
navigation systems? Which influence on individual travel behaviour does the use of a navigation
system have?
The survey covers the following aspects in particular:
•
•
•
•
•
Availability and kind of navigation systems
Use of navigation system (depending on purpose of trip)
Attitudes towards use of navigation systems
Aspects of daily mobility behaviour
Potential of navigation systems to support the driver’s decision
3.2 Availability of Navigation systems
On the European market, the penetration of navigation systems has just started. In Germany,
which holds the largest market share in Europe, sales rose from 12,000 to 590,000 devices
between 1995 and 2001.(14) Other data show an increase in the sales volume of navigation
devices in Europe from 4.8 to 9.5 million between 2004 and 2005.(15) Following a study of the
Deutsche Automobil Treuhand performed in 2004, 20% of new cars in Germany were equipped
with navigation systems.(16) In comparison, navigation systems are installed in around three
percent of cars made in North America.(17)
Figures from another DLR study show that 16.2% of the German-speaking population of 16 years
and older possessed or used a navigation system in 2004. More than half of them were embedded
navigation systems (55.1%).(18)
The considerations below are based on data from the aforementioned 2005 DLR study of 1,315
owners of navigation devices. A similar situation is evident here as in the previously mentioned
2004 DLR study. 67% of those sampled possess a car embedded navigation system. 29% of the
respondents report possessing a PDA navigation system. Together with shares of 2.9% from
navigation systems on mobile phones and 9.5% in mobile navigation systems, nearly half of the
persons report owning a non-embedded navigation system (41%) (Figure 1). Here it is evident
again that users are interested in the possibility for flexible use of the navigation system. The data
taken from WIRTSCHAFTSWOCHE (15) reflects a similar picture. Here, too, the share of mobile
navigation systems (54% in 2004 and 76% in 2005) in the sale volume of devices in Europe
expressed in millions of units is very high for retrofitted navigation systems (Figure 2).
Figure 1: Kind of navigation systems (Source: own data)
Figure 2: Sales volume of navigation devices in Europe
(Source: Wirtschaftswoche, Issue 42/2006)
3.3 Use of navigation systems
Following KOLLMANN's (13) acceptance model, it becomes obvious that the acceptance process is
not concluded at the level of action, i.e. the purchase or possession of a navigation device.
Instead, full acceptance becomes evident when the available navigation device is used relatively
frequently or with high intensity. This is the precondition for individual use of navigation systems
to have an effect on the macro level as part of the overall travel system. That means the
individual use of available navigation devices can have an impact on the utilization of traffic
infrastructure if the intensity of use is relatively high.
The following section will therefore explore the level of use. On the level of use, the performed
actions of purchasing and acquiring the navigation device are transformed into voluntary, specific
use. The analysis of the frequency or intensity of use aims to answer the question of whether
navigation systems represent deliberately used, reliable guides for users or whether they instead
tend to represent unused standard equipment.
Nearly half of the persons randomly sampled use a car on a (nearly) daily basis in which a
navigation system is available (44%). 24% go one to three times per week by car with a
navigation system (Figure 3). This illustrates that the possibility to be supported by a navigation
system integrated in the regularly used vehicle is in principle given. If we now consider the
individual use of the navigation system, it becomes clear that nearly 20% of the respondents use
the navigation system during (nearly) every trip and 42% often (Figure 4).
Figure 3: Use of car navigation (Source: own data)
Figure 4: Individual use of a navigation system
(Source: own data)
A highly significant correlation was shown when analysing the independence between the
frequency of use of a car with a navigation system and the frequency of use of the navigation
system. The more frequently a car with a navigation system is used, the more frequently the
navigation system is used on (nearly) every trip. With a Spearman correlation coefficient of
0.547, an average correlation exists in this regard. Just as significant a correlation exists between
the use of the navigation system and the kilometres driven with the car on average per year. The
Spearman correlation coefficients amounts to -0.346, signifying a low correlation: The more
kilometres driven on average per year, the more likely it is that the navigation device is used on
(nearly) every trip (Figure 5).
Figure 5: Use of navigation systems depending on distance travelled per year (source: own data)
When we consider the purpose of the trips for which navigation devices are used the most
frequently, it becomes clear that during vacation (long distance trips) (66%) and business trips
(31%) navigation devices are used on (nearly) every trip. In contrast, during shopping trips (3%),
trips for private affairs (4%) and trips to work (6%), the navigation device is used much more
seldom on (nearly) every trip. To the contrary, during trips for these purposes, the share of
respondents reporting that the navigation device is never used for these purposes is rather high
(Figure 6).
Figure 6: Use of navigation systems depending on trip purpose (source: own data)
Trips related to work/training, shopping and private affairs can be viewed as everyday trips.
These trips are therefore normally made in a habitual way in terms of the destination and thus the
choice of routes. In contrast, vacation and business trips are normally made less often and the
destinations and consequently also the routes are always different. People can rely less on
experience. Navigation systems are consequently used more frequently in less routine situations.
Nonetheless, 42% of those randomly sampled report also using navigation systems in regions
they know well.
The study of the use of navigation systems tends to show that owners of navigation systems
accept these beyond the positive acceptance decision in the form of acquiring the device. The
corresponding use is also evident. Consequently, the condition is met that individual use of
navigation systems can have an influence on the macro level as part of the overall traffic system.
The derivation of the effects on the overall system must ultimately follow with due regard to both
the purpose of and the degree of routine involved in the trip.
3.4 Influence of navigation systems on individual travel behaviour
To derive the effects on the overall system, we must know how navigation systems influence
individual behaviour. This extends our analysis of the acceptance process at the level of use to a
qualitative component. The level to which the information provided by a navigation device
influences the type of decision also becomes evident. Hence, not only the frequency but also the
consequences of use (i.e. the result of the decision-making process) are considered at the
behavioural level.
Starting from attitudinal acceptance, the statements made below concern behavioural acceptance.
Behavioural acceptance is also evident in the analysis in that the statements made by the
respondents are to be viewed above all in light of their own observation with the navigation
device. All respondents possess and use a navigation device.
It is evident on the level of attitudes that navigation devices for their owners not only form part of
the standard equipment but are also used, followed and seen as support (Figure 7).
Figure 7: Attitudes towards navigation systems and influence on travel behaviour (source: own data)
On the one hand, navigation devices are not only used in altered situations when people have to
change their behaviour. 67% of those sampled (often) do not agree with the statement that they
only use the navigation device when there is congestion (Item 6). Nonetheless, navigation devices
are viewed as a good aid to averting congestion (65%; Item 7). On the other hand, influence of
navigation devices on individual travel can be detected at the attitudinal level. For example,
navigation devices particularly have an influence on the choice of and change in routes and the
scheduling of the time to be expended on a trip. 34% of the respondents (often) agreed that they
travel different routes since they have possessed a navigation device (Item 1). It is also evident
that half of the respondents allow themselves to be guided unrestrictedly by the navigation device
(55%; Item 4). This is reinforced by the fact that 60% of the respondents (often) do not agree that
they often do not follow the recommendations of the navigation systems (Item 5). Nearly onethird of the respondents view the use of navigation devices as support in scheduling the time to be
expended on a trip. 32% agree with the statement that they schedule less time for certain routes
since using a navigation device (Item 2).
Navigation devices tend to have less influence on the choice of transport. On the one hand, only
8% of that sample confirmed that they use their car in the city more frequently since using a
navigation device (Item 3). On the other, only 8% agree to the statement that they tend to use
busses or trains in unknown regions without a navigation device (Item 8). The navigation device
owners surveyed are in principle people with a great affinity for cars. This is also shown by the
fact that 82% use a car on a daily basis, while 64% use means of public transportation less than
one to two times per year. In relation to the choice of the means of transport, very strong habitual
behaviour is evident here, which is independent of the use of a navigation device. The influence
of a navigation device on travel behaviour accordingly tends to be limited to motorized individual
travel and currently does not have an effect on the modal split of the general travel system.
As previously shown in the analysis of the use of navigation devices, navigation devices support
traffic participants particularly in unknown regions. In unknown regions, 44% of those surveyed
feel very insecure without a navigation device (Item 9). The share of those following the
instructions of the navigation devices is relatively high both in known and unknown regions
(Figure 8).
Figure 8: Compliance of navigation systems in well-known and unknown regions (source: own data)
In regions they know, 62% follow the instructions of the navigation device at least often. Because
only 42% of those sampled at all use navigation devices in known regions, 17% of the total
sample therefore follow the instructions of their navigation device in known regions. In unknown
regions, the share of those who (almost) always follow the instructions of the navigation system
is more than three times as high (79%) as in known regions.1
The degree of trust in and thus also the degree of compliance with the instructions of a navigation
device are evident in the fact that the instructions of the navigation device tend to be followed
more than indications on road signs. The respondents were put in the hypothetical situation that
they wanted to drive to "Körlin"2 using their navigation device. They drive past a roadway sign
clearly indicating a different direction than the navigation device. In response to the question of
how they would react in such a situation, 68% of those sampled reported that they would follow
the recommendations of the navigation system (Figure 9).
Figure 9: Following navigation system or road sign? (source: own data)
1
2
The comparison is based on the persons (n=558) who at all use a navigation device in known regions.
This is a fictive city, thus unknown to all respondents.
4. Conclusion and outlook
The acceptance of navigation devices goes beyond the decision to acquire them. It is evident that
navigation devices are also used intensively and are followed to a high degree. This is particularly
true for less routine purposes, such as vacation and business trips. This is supported by the fact
that the share of those who (nearly) always follow the instructions of navigation devices in
unknown regions is more than three times as high as in known regions.
The influence on individual travel behaviour relates as a whole primarily to the choice and
scheduling of certain routes. Precisely in congestion, navigation systems are attributed a high
degree of potential support, leading to a change in routine as a result of the instructions. The
modal split currently has a negligible influence through the use of navigation devices. This is
system immanent, as largely mono-modal, car-centred navigation systems are presently available
on the market, so that users of navigation devices are presently only seldom provided information
or directions that take into account public means of transportation. The available data also show
that navigation device owners generally have a great affinity for car use. With respect to the
choice of transport, this type of habitual behaviour does not tend to be disrupted solely as a result
of information.(19)
In order to derive the effects on the overall travel system, further analyses must be conducted. On
the one hand, the available data must be transferred and related to representative data for the
Federal Republic of Germany. The derivations of the effects on the overall system must
ultimately be made with due regard to the purpose of and the degree of routine involved with
trips. On the other hand, socio-economic aspects of users of navigation devices must also be
taken into consideration.
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