Table of Contents

3.10.1 Integration

The need for integration

The need for integration is apparent when considering problems that may occur by pursuing single‑function systems.

Various systems may rely on similar sets of data

Various traffic information services rely on similar sets of data. Traffic volume data, accident data, and weather data may all be used in various ways by various services. It would be impractical and probably impossible for every service to create its own traffic data from scratch. Usually, it would be much more efficient to separate the data collection and create a platform or protocol for shared use, allowing for sharing between various systems. Data sharing that allows for integration allows for higher flexibility and variety of services.

Fragmentation of services

It is often problematic for users to deal with separate systems or services whenever they move to a new area. While network operation is aimed to facilitate mobility, the fragmentation of services might even hinder such mobility. It is much more convenient from a user viewpoint to be able to use the same system and services seamlessly among various geographical areas and jurisdictions. A system designed with such horizontal integration in mind greatly improves the utility of a service.

Issues of human machine interface (HMI)

Many services that enhance network operation require user interaction within the vehicle, often while driving. Lack of consideration for other systems would lead to a random assortment of proprietary displays and input devices, especially within the vehicle. The risk of driver distraction is very real, and as the number of interfaces within the vehicle increases, the risk of misuse and confusion would rise exponentially. Integrating various services could also integrate these interfaces into a more usable and understandable system.

Development cost

Many services require similar components, such as communication channels, or a common geographical database, or payment systems. If all services were developed separately, these similar components would have to be developed, tested and deployed independently, which is wasteful and time consuming.

Interference between systems

Interference between systems is another important issue. Integrated systems, if properly tested and fielded, would decrease such risk by assuring that the integrated services work properly together.

Methods of integration

There are several possible approaches to integration:

  • comprehensive system
  • integration of existing systems
  • standardisation
  • system architecture.

Table 3.11 summarises the issues associated with each. A more detailed discussion can be found in World Road Association (2003).

Table 3.11: Integration issues – summary

Integration methodObjectivesMethodRequirementOutcomesIssues
Comprehensive system designBy designing everything together, avoid redundancy and the issues of interoperability.Overall design.

Good understanding of the overall needs.

Good coordination between parties involved.

Provides uniformity of services, i.e. avoids redundancy.

Time consuming to design a huge system.

Risk of low maintainability, risk of low upgradeability and possibly difficult to adjust to new conditions (these issues could be resolved through good planning and modular approach).

Integration of existing systemsProvide wider coverage by connecting similar systems in different areas.Create an interface system.

Good coordination between the parties.

Certain level of uniformity in the services.

Possible to create a seamless wide area service.

Increased utility.

Bad integration may deteriorate the existing services.

How to filter the relevant information from the wide area information.

StandardisationTo ensure interoperability between components, services and equipment.

Activities of the standardisation bodies.

De facto process of the market.

Agreement between the parties involved.

Provides versatility.

Expand markets by allowing for competition.

Very slow process; often difficult to reach agreements.

Danger of a standard that no one uses.

System architectureEnsure the soundness of the overall structure whilst promoting interoperability.Activities of the standardisation body.

Good cooperation and agreement between the parties involved.

Good review process to allow for possibility of expansion.

Create a broad picture.

Allow various new innovations that operate on the architecture.

Very slow process; often difficult to reach agreements.

Danger of a standard that no one uses.

Possible over-complication.

Source: Adapted from World Road Association (2003).

Implementation issues

Integrating various systems is an effective approach to network operations. There are, however, a number of issues that need to be addressed (World Road Association 2003):

  • Plan ahead:
    • Achieving integration as a second thought may prove to be extremely difficult. Once a system is in place, replacing it may involve significant financial and institutional resistance. If there is any possibility of integrating various services in the future, it should be included within various considerations from the beginning.
    • In addition, various efforts to bring the players together and reach an agreement require a significant amount of time. Road network operators need to allow time for that negotiation process.
  • Short term and long term benefits:
    • An integrated system means that it may be difficult to optimise for a single application or service in the short run. Common and standardised protocols may not be the optimal solution for that particular service. For example, if an electronic toll collection (ETC) system is required only for a single stretch of toll road, it may not make sense to consider a common national system, which would require a more complex system. It should prove beneficial in the long run, but just how long may differ from place to place, and in the short run, it would be easier and cheaper to introduce an off-the-shelf ETC system.
    • The planning horizon for each operator will differ. It should, however, be noted that the decision to (or not to) integrate a system would also be affected by that horizon.
  • Existing standards versus new standards:
    • Sometimes it may prove that the existing data formats or communication protocols are not sufficient. Creating a generic and standard protocol or data exchange format, however, is not a trivial task, especially for network operation applications that are often mission critical. By integrating various services into a single communication protocol, for example, the system would have a single point of failure. The protocol needs to be extremely robust, and the testing that is required ensuring robustness will become difficult as the complexity and the importance of that module increases. In some cases, it makes sense to sacrifice the level of the service in order to achieve integration using an existing and proven standard, rather than trying to create an optimal one.

Obviously, many of the issues concerning integration are not purely technical, but institutional. The negotiation between participants, the division of labour between the private and the public sectors, the issue of acceptance, all become extremely important in an operator’s decision process.