How to Draw Flyovers
by Saikrishna Arcot

Introduction

You've just found a new highway intersection that's been built that's not in Map Maker. It's a flyover and saves some steps and time for drivers who want to change flyovers. So, you decide to add the new road to Map Maker. There's just one problem: it goes over the freeway and other roads, and drawing the road normally will make the ramp intersect with the freeway.

This guide will help you create such a flyover while making the right intersections.

Procedures

  1. First, see if there is a spare intersection near the start of the ramp and the end of the ramp. There will often be one. To do this, go to Edit > Select a Line and click somewhere on the freeway near the start/end of the ramp. Look for the intersection icon.
    If you see one nearby at both ends of the ramp, go to With Existing Intersections. Otherwise, go to Without an Existing Intersection.

With Existing Intersections

  1. Go to Add new > Draw a Line > Road Flyover / Underpass.
  2. Draw the ramp, starting with the intersection nearest to the start of the ramp and ending with the intersection nearest to the end of the ramp.
  3. Set the appropriate attributes. See the Note on Grade Levels below. Submit the edit.

Without an Existing Intersection

  1. In this case, let's say that the flyover from TX-121 to TX-183 goes from just before Murphy Drive, over Airport Freeway, over TX-121 and TX-183, over Murphy Drive again, and then joins to the TX-183. So, let's draw a short segment from TX-121 to a point before the first road it goes over (in this case, Airport Freeway).
  2. Hit Enter or click on the green checkmark to get to the editing a road screen.


  3. Now, move the end marker (Marker B in this case) to a point after the last road the flyover is going over.

  4. Set the necessary attributes, including the grade levels of the road. See the Note on Grade Levels below. Also, you might want to keep the default priority (Local Road) and not set the segment usage just yet since that will send the edit into moderation.
  5. Submit the edit.
  6. Now, you need to draw the last segment of the ramp: the end of the first part you just drew to the freeway itself. This part is easy: just draw the segment!
    Remember to extend the name that is already on the ramp rather than create a new name.
That's it! Just repeat for the other ramps for the freeway, and you will have added flyovers to highways in no time!

A Note About Grade Levels

Most of the time, for a flyover, it will be something like Surface/Overpass 1/Surface. If you already have a road at Overpass 1, then set it to Surface/Overpass 2/Surface. The grade levels will affect the rendering of the road and will determine if an intersection is created for a newly drawn road. Note that this will not affect intersections with already existing roads. See Grade Levels for more information on this.

References

Jay Cotton's article on Flyovers and Underpasses

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