The Newbie File

Posted by indyroads on 1 August 2014 in English (English).

Welcome to OpenGeofiction. Be creative and have fun!

Here are some important notes regarding roadway design.

Motorways, Freeways, Auto-routes, and the like are dual carriage-ways and both directions of the motorway should be drawn.

streets should be “connected” at intersections. many new cities show them simply overlapped. if it crosses and is not a grade separation (aka bridge tunnel) it should be connected at that point with a node.

If you desire you can add traffic signals to your intersections.

Bridges should not be unnecessarily long. and make sure to place it on the appropriate layer (such as Layer = 1) or where two bridges cross. Layer 1 and Layer 2 for the second bridge that is higher. 3, 4, 5, etc. same thing with tunnels and subways (layer = -1)

I am sure there are more pointers but these are a few to start.

Comment from wangi on 1 August 2014 at 15:13

Separation between lanes… Some real-world examples:

  • UK: M25 at Crews Hill north of London is 3 lanes either side and the separation between way is 15m
  • UK: M6 TOLL east of Sutton Coldfield is 3 lanes either side and the separation between way is 20m
  • Germany: A 4 west of Kreuz Köln-Süd is 3 and 5 lanes and is 20m separation between ways
  • US: Houston’s Beltway 8 west of the I 45 junction is 4 lanes either side and is 25m separation between ways; 70m between the frontage roads
  • US: Houston’s US 59 at Sugarland is 5 lanes either side, with 30m separation between the ways; 85m between the frontage roads
  • US: a typical distributor road in Houston (say 3 lanes each side) will have 15-18m separation between ways

Compare with roads you know.

Comment from wangi on 3 August 2014 at 01:02

FAQ: how do you create street grids? (I’ve got an answer, but I think yours is better)

Comment from indyroads on 3 August 2014 at 16:28

street grids I use the parallel copies tool and then use an even spacing in the measurement section of the toolbar.

Spacing of blocks can vary as it does in any city. Many blocks can be 100m (or 330’) of some 125m (or 410’) I have even see rectangular blocks like those in NYC. such ans 100m X 200m (330’ X 660’) I have done 440’ blocks and even 1/8mi (660’), 1/10mi (528’), and 1/16mi (330’) blocks as well

to make them perfectly perpendicular use the angle tool by pressing (a) after selecting the line tool and you can create a 90deg angle . then just separate (press P) the line at the corner node and move tehn into the start position you want and make parallel lines at the spacing you have chose.

Dont forget to connect the lines at each node (you can use the line tool and click on each intersection and hit [esc] so that it will connnect the intersecting lines as a node.

This is the only way I have found to do this precisely. There is a parallel grid add-on module that you can download but it doesnt work as desired.

BTW if there is an easier way of doing this please share. creating grids can be somewhat time consuming.

Comment from isleño on 3 August 2014 at 19:37

I think the biggest challenge of making grids is actually the irregularities. At first glance a grid may seem easier than other city layouts. For example, Chicago appears to be a very regular grid city:

You can see some exceptions to the grid, but they don’t seem too prevalent. But if you actually circle each and every one, you get something like this:

Some of these are simple gaps in the grid, like for a park or a public building or a train yard. But most of them are other irregularities without an obvious explanation. Sometimes the grid rotates 90 degrees, sometimes the blocks get wider or narrower. Sometimes extra streets are added in, sometimes there are dead ends, sometimes streets do weird things when they get close to a diagonal. If you color in all the exceptions, it turns out roughly half the map area does not conform to the grid:

Not every real-life grid city is like this, but typically they are (or even more so). And these irregularities can be hard to imitate, which means there’s no quick and easy way to do a realistic grid. Yes, you want to use tools to make your lines perpendicular and spaced at regular intervals. But even if there was a way to easily crank out dozens of identical blocks all at once, it would take a lot more additional work to make it look like a typical grid city in the real world.

Hope this helps!


Comment from wangi on 9 August 2014 at 02:58

Missed this, only thing I can add is:

  • With parallel copies once the scale goes over the kilometre mark you’re +/- 100m with the measurements (which = some real life irregularities for isleño in Gobras City)
  • Shift-I is your big friend for merging ways / intersections – it’s part of “utilsplugin2” i think

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