Dynamic RTPI and MTA in public transport

Posted: 30 April 2009 | Stefan Gemperli, Head of Sales, Continental Automotive Switzerland AG | No comments yet

To make local and regional public transport more attractive to a large potential ridership and thus more competitive, passenger information is one of the critical success factors and, therefore, pivotal. While dynamic real-time passenger information at stops has become a widely accepted standard, intermodal in-vehicle dynamic passenger information that includes information on available transfers at […]

To make local and regional public transport more attractive to a large potential ridership and thus more competitive, passenger information is one of the critical success factors and, therefore, pivotal. While dynamic real-time passenger information at stops has become a widely accepted standard, intermodal in-vehicle dynamic passenger information that includes information on available transfers at next stops is not yet common.

Based on the VDV-453 real-time interface which forms one of the standards underlying the CEN “Standard Interface for Real-Time Information” (SIRI), Continental – Public Transit Solutions has successfully put into operation a real-world installation in Switzerland. The company is now advancing this solution on a larger scale with another Swiss transport association.

Solution approach

Studies show that topical information influences passengers’ perception of how long they have to wait for their next bus or tram. This is not only valid for the beginning of a journey, but also plays a significant role during the trip. Therefore, operation of public transport is perceived as more reliable, more on time and more convenient.

Hence, system integrators such as Continental – Public Transit Solutions have been striving to provide local public transport authorities with means to enhance in-vehicle information in such a way that passengers learn in real-time about available transfers at next stops already in the feeder vehicle (and not only after they have reached the stop). A corollary of this is that transport authorities must be able to ‘guarantee’ the transfer by ordering the receiver vehicles to wait for the incoming feeder vehicles.

Although this concept is generally termed ‘transfer protection’ in the public transport industry jargon, we prefer to refer to it as ‘managed transfer availability’ (MTA). The MTA concept aims at making the highest number of planned transfers available to the passenger.

To achieve this, an approach comprising of two steps has been chosen:

  1. Within a pre-defined time slot, the system automatically orders the receiver vehicles to wait for the feeder vehicles
  2. As soon as this time slot has lapsed, the system warns the dispatcher in the control centre that from now on the decision is his to keep the receiver vehicle waiting (see Figure 2 on page 60).

Therefore, any technical solution has to make adequate and dedicated information instantly available to passengers and drivers alike and yet must ensure that securing a reasonable number of transfers does not lead to slowing down local public transport at a network level. This is even more important when not only a single public transport authority is involved but different operators at local, regional and even national levels.

Core technology

The core technology behind the solution implemented by Continental – Public Transit Solutions is the VDV-453 real-time interface which forms part of the basis of the SIRI “Standard Interface for Real-Time Information” that has been recently defined by the European Committee for Standardisation (CEN 15531). The Swiss National Railways (SBB) dubbed their SIRI implementation project “CUS”.

SIRI is defined by the CEN as a communication layer which defines common procedures for requesting and exchanging public transport data, hence an interface between control centres of Automatic Vehicle Monitoring Systems (AVMS) or AVMS with these functions.

Figure 3 on page 60 illustrates the basic set-up of this interface.

The scope of this interface is described by the CEN as a system architecture to exchange traveller information data between public transport operators or multimodal operators about time schedules, network events or waiting time.

According to the CEN, the objectives of SIRI are fivefold:

  • To provide real-time service information to passengers
  • To provide information to journey planners
  • To facilitate transfers for passengers
  • To manage both fleet and network
  • To enable general business communication

First implementation by Continental – Public Transport Solutions

Fully functional intermodal real-time passenger information has been implemented by Continental – Public Transit Solutions in the Swiss city of Zug and its surrounding area which is situated approximately 30 kilometres south of Zurich in the heart of Switzerland.

This catchment area is mainly served by the regional bus authority ‘Zugerland Verkehrsbetriebe’ (ZVB) and by the ‘Stadtbahn Zug’, a regional light rail system operated by the Swiss National Railways (SBB). In this setting, the ‘Stadtbahn’ vehicles act as feeders, the ZVB buses as receivers. In the light rail vehicles, passengers are not only informed of the actual departure times of the buses waiting at the next stop but also of the impending departures of regional and national trains at the next train station.

This highly innovative solution has been jointly implemented by Continental – Public Transit Solutions, ‘Zugerland Verkehrsbetriebe’ and the Swiss National Railways.

Latest implementation

Continental – Public Transit Solutions is currently implementing a very advanced Automatic vehicle location and control (AVLC) system for the ZVV which serves the greater Zurich Area and is Switzerland’s largest transport association (see Figure 4 and Figure 5 on page 61).

Unlike the afore mentioned system previously implemented in the Zug area, the AVLC for ZVV will provide not only train passengers with the actual bus departure times but also bus passengers with real-time information on regional and national train departures. Therefore, passengers in all feeder vehicles will learn of all transfers available to them at the next stop regardless of whether this is a city bus, a regional bus, a regional light rail train or a national train.

This intermodal real-time approach will be the first of its kind that is technically capable to provide public transport users with seamless travel information along their entire travel chain (see Figure 6).


Before they even leave their home or office, they have access to topical travel information via the Internet or handheld mobile devices such as mobile phones.


Once they have reached a bus stop or a train station, they are informed on all actual departure times at a given point in time. Both electronic information signs and smaller devices as small as the size of a sheet of paper can act as information media.


As soon as they have boarded their public transport vehicle – be it a bus, a tram, a regional light rail or a national train – they are kept updated in real-time on all actual departures at the next stop as well as on all currently available transfers. Where feasible, they are presented with travel alternatives in case of network events such as significant delays or partial network congestions.

In-vehicle intermodal real-time passenger information

In the system implemented for ZVV, all in-vehicle passenger information is displayed on the ‘Multi Functional Display’ (MFD). This component displays topical information in a location-dependent sequence of specific screens. The underlying display strategy is based on segmentation. The meaning of this is twofold: Firstly, it means that every stretch between two stops is fragmented into three so-called ‘path segments’ and, secondly, that while the vehicle is standing at a stop the time is fragmented into three so-called ‘time segments’:

The idea behind the segmentation is that ‘Path 1’ and ‘Path 3’ as well as ‘Time 1’ and ‘Time 3’ are the important segments, while both ‘Path 2’ and ‘Time 2’ are fillers in between. The system automatically omits segments that cannot be executed entirely and stretches other segments so that no pauses occur. For every segment, a layout or sequence of layouts can be configured.


Apart from enhancing travellers’ convenience, this intermodal real-time passenger information solution enables transport authorities to manage and utilise their transport infrastructure more effectively, i.e.:

In case of network disturbances, for example, travellers can be advised to use those parts of the network that are still functioning by providing them with up-to-date travel recommendations

The intermodal real-time passenger information interface is not limited to local or regional public transport – it can provide information on all kinds of means of transportation, even planes. Thus, seamless travel information in real-time from the door of your home to the boarding gate of your airport no longer remains a utopian idea


All information presented in this paper is derived from the following sources:

  • Continental Automotive Switzerland AG project documents
  • CEN Report N1830 of WG3 to the 36th Plenary Meeting of CEN/TC 278 in Sevilla by Convenor Jean-Laurent Franchineau, March 22, 2003 (


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