Ghent – Citizens evaluate impact of closing a bridge for traffic

CHALLENGE

How best to visualise the simulation of the impact of a road closure on the traffic in the surrounding streets in an unambiguous and comprehensive way?

That was the question that triggered the DUET technical team to create the delta layer.
The delta layer shows – at a glance – where traffic volumes increase due to an intervention (pink colours) and where they decrease (green colours).
By using colour gradients, visitors immediately get an idea of the extent of the impact. More intensive colours indicate higher impact.

STATUS : started

LOCATION : Belgium, Ghent

TARGET AUDIENCE : Citizens

APPROACH

The two-colours-gradient delta layer did not combine well with the multi-coloured OpenStreetMap base map. That’s why we created a greyscale version of the base layer, making the delta layer stand out better. We also optimised the colours used for people suffering colour blindness.

EXPECTED OUTCOME

In preparation for this testing, specialists set up the simulation of the blockage of road segments. Traffic models calculate the effects in the surrounding streets. All calculations are bundled in an export layer.
You, and every other visitor can make a delta layer, starting from this export layer.

How to use

If you click the link below, you see the city of Ghent, where we made a simulation of the closure of one of the main roads in the centre.

Create a delta layer by changing the settings of the simulation result layer (the gear icon). A pop-up window allows you to set-up a delta layer (the last option from the list). Select the road network as a basis for the delta layer and click the “create delta’ button.
The creation of a delta layer is a two-step process. Click the new ‘add layer to map’ button. Now the delta layer is immediately visible on your screen.
You can consult the legend explaining the colour code at any time, by clicking the information icon.
Feel free to show/hide available layers and to update the zoom level, orientation and tilting level to optimise your view. The impact on traffic is best seen if you only switch on your created delta layer, like this: