Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>The </SPAN><SPAN STYLE="font-weight:bold;">LRSN_Postmile </SPAN><SPAN>feature class is an Esri Roads and Highways Network (or more generically a Linear Referencing Method) that represents the California State Highway System (Interstates, US Highways and State Highways) using the Caltrans Postmile System.</SPAN></P><P><SPAN>The Caltrans Postmile System is fairly complex, where postmiles reset to 0.0 at county boundaries, temporality is managed through Postmile Prefixes and "</SPAN><SPAN STYLE="font-style:italic;font-weight:bold;">Independent Alignments</SPAN><SPAN>" (where right and left sides diverge around various obstacles and are postmiled differently) are managed with Postmile Suffixes. To accommodate this system, entire "</SPAN><SPAN STYLE="font-style:italic;font-weight:bold;">Signed Routes</SPAN><SPAN>" (e.g. 800+ miles of Interstate 5) are divided into a number of "</SPAN><SPAN STYLE="font-style:italic;font-weight:bold;">Postmile Routes</SPAN><SPAN>", where the Postmile Prefix and Postmile Suffix are managed as part of the Route ID, leaving just the numeric portion of the Postmile as the Postmile Route Measure.</SPAN></P><P><SPAN>Additionally, while the Caltrans Postmile System is considered a "</SPAN><SPAN STYLE="font-style:italic;font-weight:bold;">Centerline</SPAN><SPAN>" system (with the exception of the aforementioned independent alignments), the LRSN_Postmile Network stores complete right and left "</SPAN><SPAN STYLE="font-style:italic;font-weight:bold;">Carriageways</SPAN><SPAN>" (the R/L carriageway designation is also part of the Route ID). The reason for this is to best support independent alignments AND to meet Federal Highway Administration requirements for every state's Linear Referencing System.</SPAN></P><P><SPAN>To accommodate division of entire signed routes into multiple Postmile Routes, LRSN_Postmile is configured as a Roads and Highways "</SPAN><SPAN STYLE="font-style:italic;font-weight:bold;">Line Feature</SPAN><SPAN>", where every individual Postmile Route that comprises a Signed Route is tagged with a "Line ID" common to the Signed Route. This supports the ability to perform Dynamic Segmentation of linear events that begin on one Postmile Route and end on another, and the ability to automatically derive the Odometer Network directly from the Postmile Network.</SPAN></P><P><SPAN>The Postmile Network is one of three Roads and Highways Networks maintained in Roads and Highways by Caltrans. The other two are the </SPAN><SPAN STYLE="font-weight:bold;">Odometer </SPAN><SPAN>Network (also State Highway System only, and derived from the Postmile Network) and the </SPAN><SPAN STYLE="font-weight:bold;">AllRoads </SPAN><SPAN>Network, which represents all public roads in California (not just state highways).</SPAN></P></DIV></DIV></DIV>
Service Item Id: a8f799df1e6648b9b0adaeafa8089a56
Copyright Text: California Department of Transportation (Caltrans)
Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>The LRSN_Odometer feature class is an Esri Roads and Highways Network (or more generically a Linear Referencing Method) that represents the California State Highway System (Interstates, US Highways and State Highways) using continuous statewide odometer measures. </SPAN></P><P><SPAN>LRSN_Odometer is not manually maintained, rather it is created (or "derived") from the LRSN_Postmile network, where the measures (the odometers) are the running accumulation of all the individual "Postmile Routes" that make up each route in the Postmile Network. </SPAN></P><P><SPAN>Users should be aware that Odometer values are duplicated at "route breaks" (physical gaps) in state highway routes. While this meets Caltrans requirements for a continuous measure system that is based on Postmiles, at these route breaks it results in ambiguity and the inability to specify a single location based on a single odometer value. </SPAN></P><P><SPAN>The Odometer Network is one of three Roads and Highways Networks maintained in Roads and Highways by Caltrans. The other two are the Postmile Network (also State Highway System only, from which the Odometer Network is derived) and the AllRoads Network, which represents all public roads in California (not just state highways).</SPAN></P></DIV></DIV></DIV>
Service Item Id: a8f799df1e6648b9b0adaeafa8089a56
Copyright Text: California Department of Transportation (Caltrans)
Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>The LRSN_Odometer feature class is an Esri Roads and Highways Network (or more generically a Linear Referencing Method) that represents the California State Highway System (Interstates, US Highways and State Highways) using continuous statewide odometer measures. </SPAN></P><P><SPAN>LRSN_Odometer is not manually maintained, rather it is created (or "derived") from the LRSN_Postmile network, where the measures (the odometers) are the running accumulation of all the individual "Postmile Routes" that make up each route in the Postmile Network. </SPAN></P><P><SPAN>Users should be aware that Odometer values are duplicated at "route breaks" (physical gaps) in state highway routes. While this meets Caltrans requirements for a continuous measure system that is based on Postmiles, at these route breaks it results in ambiguity and the inability to specify a single location based on a single odometer value. </SPAN></P><P><SPAN>The Odometer Network is one of three Roads and Highways Networks maintained in Roads and Highways by Caltrans. The other two are the Postmile Network (also State Highway System only, from which the Odometer Network is derived) and the AllRoads Network, which represents all public roads in California (not just state highways).</SPAN></P></DIV></DIV></DIV>
Service Item Id: a8f799df1e6648b9b0adaeafa8089a56
Copyright Text: California Department of Transportation (Caltrans)