Defining Segments

Segment definitions are constructed from three components. The first is two pairs of coordinates arranged as x1, y1, x2, y2 in the screen pixel coordinate system. This specifies the endpoints of a road segment. (Note that the specification of segment width, segment border width, and the coupling of color to loops data value is specified in the Segment Type Definitions section of the map configuration file.)

The second component of each entry is a cap style value. This indicates whether the connecting lines at each end of the segment are to be drawn horizontally or vertically. If the style is "1", the end lines are drawn vertically; otherwise, the end lines are drawn horizontally.

The last component of each entry is the 15-character loop identifier that maps the roadway sensor data onto the segment. Roadway data is obtained from the generic redistributor (the real-time data gathered in the \TrafficChannel\segmentLogger\sdd.output). The value of the data is used to select the color for the segment.

Single line comments can be entered in the segment definition files using the # symbol.

Segment definition files are stored in the \TrafficChannel\SegmentDefinitions directory. The following sample is a partial listing from the PugetSound.seg file, which is used for both of the "Mainline" traffic displays.

148 267 157 267 1 ES-502D:_MW_Stn  # 520 west
157 267 166 267 1 ES-504R:_MW_Stn  #
166 267 175 267 1 ES-506R:_MW_Stn  #  
175 267 184 267 1 ES-506R:_MW_Stn  #
184 267 193 267 1 ES-506R:_MW_Stn  #
193 267 202 267 1 ES-506R:_MW_Stn  #
202 267 211 267 1 ES-514D:_MW_Stn  #
211 267 220 267 1 ES-516R:MMW_Stn  #
220 267 229 267 1 ES-519R:_MW_Stn  #
229 267 238 267 1 ES-520D:_MW_Stn  #
238 267 247 267 1 ES-521R:MMW_Stn  #
247 267 256 267 1 ES-524R:MMW_Stn  #
256 267 265 267 1 ES-528D:_MW_Stn  #
265 267 274 267 1 ES-531R:MMW_Stn  #
274 267 283 267 1 ES-533D:_MW_Stn  #
283 267 292 267 1 ES-535D:_MW_Stn  #
292 267 301 267 1 ES-538D:_MW_Stn  #
301 267 310 267 1 ES-541D:_MW_Stn  #
148 280 157 280 1 ES-502D:_ME_Stn  # 520 east 
157 280 166 280 1 ES-504R:MME_Stn  #
166 280 175 280 1 ES-506R:MME_Stn  #
175 280 184 280 1 ES-506R:MME_Stn  #
184 280 193 280 1 ES-506R:MME_Stn  #
193 280 202 280 1 ES-506R:MME_Stn  #
202 280 211 280 1 ES-514D:_ME_Stn  #
211 280 220 280 1 ES-516R:_ME_Stn  #
220 280 229 280 1 ES-519R:MME_Stn  #
229 280 238 280 1 ES-520D:_ME_Stn  #
238 280 247 280 1 ES-521R:_ME_Stn  #
247 280 256 280 1 ES-525R:MME_Stn  #
256 280 265 280 1 ES-528D:_ME_Stn  #
265 280 274 280 1 ES-531R:_ME_Stn  #
274 280 283 280 1 ES-533D:_ME_Stn  #
283 280 292 280 1 ES-535D:_ME_Stn  #
292 280 301 280 1 ES-539D:_ME_Stn  #
301 280 310 280 1 ES-541D:_ME_Stn  #

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(May 11, 1998)