Right now we are working on a ginormous road schematic or uber road schematic – we have lots of huge words to describe it because it is HUGE!! The idea is to combine all the road schematics for one region for one operator onto one schematic and that seems like a really good idea – on the surface. Below that mill pond of logic roils a heap of factors affecting the viability of the outcome, some technical, some about visual language.
We will eventually have about 8 road schematics to put onto one big, uber, gigantic road schematic. Usually road schematics are long skinny things that use up the full width of the art board available in Adobe Illustrator. Intersections are shown in their true configuration and shape. The shape of the intersection itself is a landmark. Not being maps, road schematics use geography to provide recognition, not accuracy. We straighten the roads and retain enough curve and shape to indicate real geography. Landmarks are included to help the operators orient themselves along the road.
The options for combining lots of roads into one schematic parallel the options for public transport network maps:
1. match the geography
2. stylise the geographic relationships using a fixed set of angles
3. establish a grid and set of fixed angles that don't relate to geography
4. lay out every line parallel to each other
The requirements for road schematics are different to public transport maps. Users of public transport maps don't need geographic detail. They only need the stops to be in the right order and approximately the right direction. Spacing the stops apart in relation to distance can also be useful.
We tried stacking the road schematics one on top of the other like a wood stack. What became immediately obvious is that some intersections appear on more than one road schematic. This created an interesting visual dilemma: when the identical intersections don't appear in line with each other vertically it creates a kind of visual confusion. But making them appear directly under each other is worse because the road each side of the intersections aren't the same. The existing schematics are basically horizontal and landscape in format regardless of the direction of the road: north-south roads have to appear running east-west. This works just fine when viewing each separately. But for schematics of different roads that pass through the same intersection, the geography is wrong when they appear stacked together.
Our best option then is to match the geography. By making the whole schematic represent the real geography then we achieve the following: the existing schematics still make sense; the relationship between the roads can be shown and the visual language remains intact. Some of the existing road schematics will need a bit of bending to make them fit the real geography. The geography still only needs to be representative: north needs to be north and what sits to the east of something needs to appear on the east but it doesn't have to be accurate, just recognisable. This is the backbone of the existing visual representation of geography: recognisable not accurate.
Once the decision to represent the real geography is made, the technical issues need to be sorted out. The two major limiting factors are the art board size and the file size. The art board size limits the width of the drawing we can produce. The file size greatly limits the amount of detail we can include. File size is a limiting factor when we produce just one road schematic but combing several onto the one art board requires some fancy footwork to fit all the art into an unchanged file size. We have to work out how to represent the same features using curves with less points, gradients with less gradient. And we have an existing road schematic visual language that we designed here at Hothouse Design and need to retain because it works, it is familiar to the operators, it is used by most of the users of STREAMS (a road management system) and it is functional.
The final super schematic is a deeper schematic but not a wider one. It has the benefit of retaining the current visual language and current representation of geography. It is readable the same way as all the current road schematics.
Maintaining the same visual language across all road schematics makes sense in the same way that all maps in a street directory or GPS system look the same. Consistency of design enables clarity and understanding – as long as the design is readable in the first place!