Orthogonal projection of observed address (latlong) cases onto road network.
latlong.ortho.addrA data frame with 7 variables that records the position of the orthogonal projection of the 321 cases onto the network of roads.
road.segment"address" road segment
x.projx-coordinate
y.projy-coordinate
ortho.distorthogonal distance to home road segment
casenumeric case ID
lonlongitude
latlatitude