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Intelligent Speed Adaptation (ISA): a research design for an experiment in the Netherlands

 

An important part within developments in the field of telematics is the Intelligent Speed Adaptation (ISA). Especially in Sweden, where the policy objective is to have zero fatalities or seriously injured victims on the roads in the year 2020, research has been conducted on ISA during the last 10 years. Intelligent Speed Adaption (ISA) can be done in several ways:

 

The information about local speed limits can be obtained in different ways:

With GPS it is known at every moment where the vehicle is, and what the speed limit is. Current data can be transmitted to the vehicle, so that a lower speed limit is installed as soon as, for example, there are poor weather conditions, or road works ahead.

In some new cars, especially the more expensive brands, a maximum speed can be manually adjusted. A warning signal is given when this speed is exceeded. Some systems even make exceeding the adjusted speed limit impossible because the fuel supply will then automatically be cut off (R-98-52).

 

Acceptation by the driver

An important question is the extent to which ISA is accepted by the driver. From Swedish research it is known that after experiencing ISA's obligatory speed reduction, the acceptance is greater than beforehand. When car drivers have the choice between an ISA system and speed control humps (or other infrastructural measures), they choose for ISA. In general, a warning system is preferred above a system that limits the speed.

The acceptance is also greater when the problem situations are recognizable: in residential areas, on roads where fast and slow traffic are not separated, at the approach of complex intersections, at road works, and during bad weather conditions, etc.

 

Influence on driver behaviour

ISA can also influence driver behaviour. Some Swedish studies show a reduction of the average speed, a more constant speed, an increase in travel time and and increased alertness towards other road users.

 

The Dutch experiment

In the Netherlands, a practical experiment with intelligent speed adapters (R-98-54) will be carried out in the borough of Tilburg during the period 1998-2000.

The goal of this project is to:

 

Different activities

In the realisation of the project, three types of activities can be distinguished:

SWOV was asked to make the design of the research plan.

 

Conditions

The following conditions apply to the further elaboration:

At a later stage it was suggested to use a GPS-guided system instead of a beacon-guided system. However, this has not been taken as a starting point for further elaboration.

 

Assumptions

The possibilities have been looked at of introducing experimental variations for a number of aspects. By this is meant especially: the 'hardness' of the system, the system's intelligence, the recognisability of the ISA vehicle, and the system of speed limits in the Campenhoef district. Although not all choices are to be considered as definite, the elaboration of the research plan assumes the following:

 

Research design

The chosen research subject follows the model of a before-during-after study, with three distinguishable experimental groups, plus control-groups. The three experimental groups will consist of:

In determining the ISA sample there is a possibility of choice between participation by individuals or by families within which more than one person can use the ISA vehicle. The preference is for the second possibility.

 

Measurement scheme and experts

The point of departure for setting up the measurement scheme is a coherent system of measurements of the fields of knowledge, outlooks and support with regard to ISA, speed behaviour, and interactions or conflicts with other road users. In addition, for the ISA sample, there will also be observations about the operation and ergonomics of the system; its effects on fuel consumption and emission, as well as specific experiences of use and specific judgements.

A number of experts are needed to execute the complete research plan. Their specialities need to be from:

 

Priorities

The research plan thus designed should be seen as a maximum programme. Some parts can be omitted for practical or budgetary reasons. To arrange the thoughts on this, the following order of priority can be indicated, in terms of those parts which should be carried out first of all, or, in any case, at some time:

When some parts of the programme are omitted for practical or budgetary reasons, the minimum programme should at least give information on the effectiveness of ISA; and it also should tell something about the acceptance of the system.

Within such a (maximum) plan it is, in addition, possible to add or link certain parts that can be included to a greater or lesser extent. Among others these are:

SWOV Research Activities 11 - March 1999

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