The project increased efficiency in the digital modelling of street junction areas and developed quality requirements related to it.

What kind of problem did this project try to solve?

Streets are usually designed using model-based design software. Digital modelling for street junction areas differs considerably from modelling for road junctions, and it does not have the same kind of standardised methods as road design.

There are a lot of minor details involved in the design of street junctions – often a street area will contain lots of equipment and cables that pose challenges for those preparing the models. The special characteristics of street design include the large number of junction areas, the diversity of drainage plans, light traffic lanes, pedestrian crossings, elevations, parking pockets, bus stops, middle lanes, kerbs and sett paving.

The modelling of streets is often also significantly more expensive than traditional design. Moreover, the current general infrastructure model requirements disregard the design of street areas, focusing instead on roads.

Objective: to increase efficiency in the design process for street junctions and to improve its guidelines

The objective was to make the design process for street junctions more efficient so as to find a balance between cost and benefits. The concrete target was to speed up the modelling of junction areas by about 50 per cent.

A second objective was to further specify the quality criteria for street junction areas. The project prepared a list of improvement needs in the guidelines concerning street design included in the Yleiset inframallivaatimukset (YIV) (General Infrastructure Model Requirements) guideline package, which is published by buildingSMART Finland, the main special commission of the Building Information Foundation RTS.

What was done in this project?

The pilot for this project was the new Haapajoki residential area in the City of Joensuu and the process of designing its streets. The pilot studied a new way of designing street junction areas with the aim of creating an end product that serves the design process, as well as assisting execution and asset management.

Who benefits?

Engineers designing street junction areas and civil servants working for the municipalities and the state.

What outcomes did the experiment produce?

Based on the pilot conducted in this project, we can recommend the differentiation of at least two different cases: the design and construction of a street in a new residential area, and that of a street located in an existing city environment.

In addition, the project prepared a list of development needs for the Yleiset inframallivaatimukset (YIV) (General Infrastructure Model Requirements) guidelines. The project focused on the construction design stage but, based on the pilot, clear requirements have also emerged for preceding design stages.

During the project, it was obviously detected that the current guidelines need to make a clearer distinction between model-based design and the data transfer files generated from it.

Data transfer files mainly consist of lines, dots and surfaces which the next user must process further, depending on the purpose of the object. Current design software forces designers to work on a so-called model basis. An export of the data model files from the software does not generate immediately usable data transfer files for all structural elements. However, it is not practical for designers to generate fully finished data transfer files that will possibly be discarded in subsequent stages. It is more worthwhile for them to focus on material that will clearly provide a benefit.

Optimisation of cost-efficiency and quality requirements in the modelling of street junction areas
Duration: 6 June–30 November 2017
Implemented by: City of Joensuu, Civilpoint Oy and Ramboll Finland Oy.

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