How Iv utilises smart tools and bright minds

The N241, better known as the A.C. de Graafweg, will undergo extensive work in the coming years. The provincial road, which runs through the municipalities of Medemblik, Opmeer and Heerhugowaard, is considered dangerous and requires intervention. The road will be widened, and a bypass will be built. All these changes affect the infrastructure and the geography. Iv has a vital role to play in the entire process. The engineering company is responsible for the complete review of the project and for updating and expanding the Geographical Information System (GIS). The redesign of the N241 is divided into three phases, the middle of which has now been completed.


The work includes widening the lanes from 6.10 metres to 7.60 metres. Fewer entrances and exits will make the road safer for cars and heavier traffic, and the bicycle lane along the 12-kilometre route will be widened. The bicycle lane will also be moved further away from the N-road to create more space between cyclists and motorists.


Michel Ham, project leader at Iv, is responsible for reviewing the work carried out and updating the GIS database of area data for the province of Noord-Holland. The work will be conducted in three phases. Iv’s work always follows the completion of a phase. The first revisions and the corresponding GIS data have now been delivered.


A revision is nothing more or less than a complete overhaul. Iv measures all changes at a detailed level. For example, green surfaces, asphalt surfaces, and separate layers for culverts, maintenance holes and pipes. Each object has a separate layer. The province of Noord-Holland defined these geometric and attribute requirements in advance. The province of Noord-Holland is a pioneer in this area; few other provinces go into such detail and depth. The GIS database is very extensive.


Iv adopts several steps throughout the project. The new situation is mapped using our own advanced 3D scan car, which takes 360-degree photos of the situation and then generates a point cloud from the results. This is then used to map the new situation. Cables, pipes, civil engineering works, asphalt and green data are collected first. In short, measurement first, GIS second.


Engineering company Iv was asked to work on this project because of its specific and extensive expertise. Iv is at the forefront in the field of automation and digitalisation. For example, Iv uses Feature Manipulation Engine (FME) software, which streamlines all collected data between geometric and digital formats. This software is specifically designed for GIS systems and computer-aided design software such as AutoCAD.


The FME software was written and programmed by Iv for the area data of the province of Noord-Holland. Everything within this software is linked together using various building blocks. Iv also builds various checks into the database to check for any gaps or overlaps in the file. The checks are fully automated and take only a few minutes. Based on these automated checks, streamlining continues until the correct result is achieved.


In addition to quality, this method of collecting GIS data delivers more. The error rate of this method is low, and the efficiency is high. Of course, manual work and human input remain necessary, but with this data collection and processing method, the information provided is one hundred percent dependable.

High requirements

As a result, the entire review and collection of data is highly accurate and complete, ensuring that the high requirements of the client, the province, are met. The province is the road authority for the N241 and is responsible for the GIS database.


Given the size of the section – about twelve kilometres – and the significant changes, a lot will change in the GIS database in terms of visible aspects, such as roundabouts where crossings were previously situated, renovated green spaces, relocated VRIs (traffic control systems), and subsurface elements. Sewers, culverts and maintenance holes will also be relocated as part of the work. As a result, a lot will change in terms of subsurface drainage, which will also necessitate a subsurface revision. A subsurface revision is logically more complex than a surface revision. Good communication with the contractor is, therefore, essential.


When a section of the N241 is opened up for construction work, everything is measured immediately before the road is ‘closed up’ again. The contractor shares all the subsurface data with Iv, including data on cables and pipes. Every loop to an electrical box, every cable to a lamppost or traffic installation must be thoroughly calculated in detail. Accuracy is key because knowing where everything is when the work is complete is crucial.

Beyond BGT

The requirements set by the province of Noord-Holland reach far beyond what the entire process must meet: the so-called BGT requirements. BGT (Basisgegevens Grootschalige Topografie) is the Dutch acronym for Basic Registration of Large-Scale Topography. All stakeholders, such as municipalities, water boards, provinces, and the Directorate-General for Public Works and Water Management (Rijkswaterstaat), can consult these maps, so they must always be current. Which section of the road was built when? What does this green strip consist of, when was a particular culvert installed, and where are the cables for traffic control systems? The GIS database of Noord-Holland is as detailed as it can be, thanks in part to the expertise of Iv.


It is crucial in this type of work that there are no gaps or overlaps between the surfaces. For example, a paved surface near a bypass is not allowed. There must be no gaps or overlaps between the hard shoulder and the verge. We can adequately map, check and deliver this using the above software and the expertise of Iv’s GIS consultants.


Iv’s work has now begun. After months of preparation, the first and middle parts of the redesign have been completed. We must wait for the contractor to complete the next phase before continuing.

Collaboration is crucial

Annual updates and adjustments to the tools that will be used are necessary to meet the standards and the requirements defined by the province of Noord-Holland. Michel Ham sees the versatility of such projects as a plus point: “It’s great fun to involve different disciplines – performing measurements, working with GIS and collaborating with Boskalis to provide data. The consultation and contact with Boskalis and the province are crucial. You depend on each other. That collaboration is fantastic.”


The A.C. de Graafweg (N241) redesign is a multi-year project. Work is currently in full swing. Due to the redesign, part of the A.C. de Graafweg will be closed until June. This is the last of five road closures to take place during the works. All the drinking water pipes have been relocated, and the work associated with the cables and pipes is complete. The provincial road is expected to be completed by mid-2025. The revision and collection of the new GIS data will also take at least until then.

Curious about the possibilities for your project?

Wouter, managing director Infra and also COO of Iv, would be delighted to discuss this with you! Get in touch via +31 88 943 3200 or send a message.

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Wouter van der Wiel