Interstates

The general rule for route dominancy is: among all concurrent routes, the route with the lowest sign system code dominates. If more than one route shares the same lowest sign system code the one with the smallest route number dominates. Measures embedded in routes are derived by linear interpolation based on calibration point data collected by using a Distance Measuring Instrument (DMI) except for ramps which use the geometry length to derive measures. Collection of all Interstates designated Sign System 1 in the Linear Referencing System as extracted from the Dominant Routes Layer in West Virginia. Current feature information included in this layer is the ROUTEID, Label, Sub Route, Sign System, Supplemental Code, Route Number, County Code, District, Beginning Mile Point, Ending Mile Points, Comments, Year Recorded and State Code. Data is in NAD_1983_UTM_Zone_17N coordinate system. Data is updated semi-annually.路由主导性通用规则如下：在所有并发路由中，信号系统代码最低的路由具有主导地位。若多个路由共享同一最低信号系统代码，则路由编号最小的路由占据主导权。路由内嵌的度量值通过线性插值法推导得出，推导依据为使用距离测量仪（Distance Measuring Instrument, DMI）采集的校准点数据；坡道除外，其度量值采用几何长度进行推导。本数据集提取自西弗吉尼亚州主导路由图层，包含线性参考系统（Linear Referencing System）中被指定为信号系统1的全部州际公路。该图层当前包含的要素字段包括：路由ID（ROUTEID）、标签（Label）、子路由（Sub Route）、信号系统（Sign System）、补充代码（Supplemental Code）、路由编号（Route Number）、县代码（County Code）、区域（District）、起点里程点、终点里程点、备注（Comments）、记录年份（Year Recorded）以及州代码（State Code）。数据采用NAD_1983_UTM_Zone_17N坐标系，每半年更新一次。