Our sign inventory has not been fully completed or field truthed yet, however we got it started with interns driving the City using Google Street View and using our high quality (1/4 ft per pixel) imagery to locate and identify signs. We also had an intern go through the MUTCD and create sign blade symbols Esri didn't have using a program I found online called Font Creator. Using this program the intern found a method for importing images from MUTCD(CA) .pdfs or field photos and such to create the fonts.The biggest obstacle for ArcGIS is how to map symbols for multiple signs on a single post. It is not advantageous to just have dots on a map, field crews and decision makers need to be able to visualize the different signs at each location (which ones the speed limit sign?). Trying to overcome this we tried several things but we were not successful. The project is currently stalled until we resolve how to track assemblies of multiple signs at a given location (fixed to the same pole). Can someone share some insights or ideas for symbolizing & tracking multiple signs at one location?
I am not sure whether our solution in mapping multiple signs on one pole can be adopted in ArcGIS (we have done it on open source software). The idea is to draw a line with two segments:the first segment's direction shows sign activity direction;the point between segments is the actual sign position (pole position);the end point of the second segment is the place where to draw map sign symbol.When symbolizing the feature the first segment is not drawn, it is used only for calculating sign direction field and rotating sign symbol, so you can also draw line with one segment and input angle field value manually.Sounded more complicated than it is 🙂You can see in screenshots how it looks symbolized and how it looks when drawing:http://geokods.com/#!/work/road_traffic_control
We are drawing a Linestring and symbolizing 2nd segment's both endpoints - starting point is the sign exact position and end point is the sign face on map. In DB we also automatically extract sign exact point for use in advanced spatial searches. We have also cases with signs next to each other on one pole e.g. in the middle of picture:http://goo.gl/maps/C5D27You are right, this approach requires more manual input as one must place also sign face on the map, but it is certainly more visually enjoyable, cause sign faces are drawn away from the road and the map never looks crowded. Sign faces are symbolized in map units, so it looks good in all zoom levels. It looks more like CAD system, not GIS.Actually at first we also implemented approach where each sign had a field with a vertical order number, but it was difficult to symbolize such a signs cause sign symbol heights are different. Also, map was much too overcrowded and we had to think for an approach to get sign faces away from the street.System is managing ~40000 signs (Riga city, Latvia).
What do you mean by "Sign faces are symbolized in map units, so it looks good in all zoom levels." Is this being done in ArcGIS? Is it using a reference scale setting or something equivalent?
Linear Referencing is much more flexible. It already got me everything I have in GIS for the 50,000 individual signs that were non-spatial in my database. It took a few weeks and the locations are usually within 10 feet of the actual true ground position if the description of the location and the GIS road alignments are accurate representations of field locations. With all of the LR based rules and calculations that I know now I could do the same thing today in under 1 day if all of the street names were spelled correctly.Using LR, with a single table and one event record for a sign I can create the actual position of the sign and a huge number of alternative positions by just adding alternative measure and/or offset fields and configuring alternative position layers designed for each zoom factor. The base angle for the road is automatically generated by LR and I have already derived a single calculation that has rotated all of my signs to their correct orientation according to the DOT facing field value. The only angle adjustments needed are plus or minus 90 degree rotations where field crews do not agree with real compass directions when they represent them with N, S, E, or W. Usually this occurs where signs are facing NE, NW, SE, or SW or along sinuous roads, which LR allows me to isolate and examine using SQL statements. Since most of my roads are on a grid, these adjustments are the exception rather than the rule.Using the alternate measure/offset fields I can do a single calculation after deriving a clustering factor from the actual sign measure and offset locations (I already have an LR based technique for coming up with that factor). Even if I get it slightly wrong for a given location a simple edit of a number will change the artificial sign position to make adjustments without any mouse clicks. After doing a few hundred individual locations I will derive another rule based calculation to apply to all locations as an initial default position for each chosen zoom factor. At that point I can process all the rest of the 50,000 signs for each zoom factor adjustment I want using rule based logic that can be automated and create a script for new signs captured from the field.If I complete my approach of deriving the actual assemblies for each post from multiple sign records into a single assembly record I can create a single symbol for the assembly that spaces the signs exactly the way I want vertically. The assemblies are not infinite and once the symbol is created no maintenance time will be required to achieve that perfect spacing. For assemblies that account for hundreds of sign locations the time spent on the assembly symbol will be next to nothing compared to manually adjusting the individual signs at each of those locations. The problem is diminishing returns when I have assembly combinations that are only used in just a few locations. But in the majority of those cases I still have yet to spend time designing an individual sign face anyway and designing one assembly sign face instead will not consume much more time over designing two or three separate sign faces.After all of the sign assemblies and sign faces are completed, the process I am envisioning will be nearly fully automated using rule based logic from the data captured by the field worker to achieve a more than acceptable presentation. An optional refinement process using a few localized field calculations can do any perfecting of the positions and rotations when an area is chosen for an actual presentation.
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