Meso-simulation

Meso-simulation is a particular traffic modelling application that analyses the impact and performance of changes in the road network at an intermediate scale of urban environment (a district or neighbourhood). It may also be useful for predicting the impact of new transport flows in the interchange urban vicinity or for testing alternative schemes.

Following the same logic of macro-simulation – sometimes even the same software platform – meso-simulation analyses a particular area in detail: usually an urban environment, such as a neighbourhood or a city district.

The accuracy of the network for that area is therefore better, as well as the amount and level of the results, which may be disaggregated sufficiently for that particular urban area and its corresponding network.

Mesoscopic simulation fills the gap between the macro, aggregate level and the individual interactions of vehicles in micro-simulation.

This kind of analysis is useful when a particular change is going to be introduced and its impact is expected to affect a wide area: a new tunnel/bridge, a reduction of lanes in streets, the substitution of traffic lights for roundabouts along a major road, etc.

This is the case for a new interchange and the new flows that it may involve, as long as not all transport modes are segregated.


NODES strategic objectiveContribution
Enhance accessibility and integration ++
Enhance intermodality 0
Enhance liveability +
Increase safety and security conditions ++
Increase economic viability and costs efficiency ++
Stimulate local economy 0
Increase environmental efficiency +
Increase energy efficiency +

Good practice

This tool is common worldwide and has been used in many projects, even if reports are not always publicly available Study cases can be found in the work of Halslof Holst (see References).

Application in NODES sites:

This tool has been tested by the city of Reading.

The Reading team notes that “it is clearly of great importance to judge the right tool modelling” and that “this is a matter of skilful interpretation and experience. The ‘results’ of any given model may not in fact be the right answer”.

Nonetheless, Reading claims that “the use of this tool prevented a major construction error which would have been extremely costly to rectify later.

Reading rated this as a 3-star (***) tool.


Potential interchange performance improvement

Estimating the impact of the interchange-based flows, according to traveller behaviour and individual vehicles movements is crucial:

–          To understand expected impacts on traffic congestion over a wider area.

–          Consequently, to identify points or streets of potential conflict.

–          To evaluate and compare different alternatives.

 


Resources

A team of experts is required during the process and for the interpretation of results, as well as a normally expensive software licence.

References

HARSLØF HOLST, R.A. (2007): Maso-, Meso- and Micro simulation – A comparison of three DTA softwares. Center for Traffic and Transport – Danish Technical University. (available online)

PAPAIOANNOU, POLITIS & BASBAS (2008)  “The Role of Transport Planning Software Tools, on Modelling Transport Systems and Evaluating Their Performance”, 3rd International Conference: From Scientific Computing to Computational Engineering, 3rd IC-SCCE, Laboratory of Fluid Mechanics and Energy, University of Patras, 9-12 July 2008, Athens, Greece, pp 1-9

 

Main software products and providers:

Ainsum, by TSS

Cube Avenue, by Citilabs

Dynameq, by INRO

Transmodeler, by Caliper 

Note: Many macro- and micro- simulation software can be adapted to perform meso-scale analysis.