HERE Fleet Telematics API (Custom Locations)
Fleet Telematics Custom Locations Developer's Guide

# Searching along a Route's Isoline

This section clarifies the 3 different functions Isoline Routing, Search along Route Isoline and WSE Pickup along Route.

Routing offers Isoline and Reverse Isoline functions. As shown in the figure, the result is a polygon covering all road links that can be reached from the given location (polygon on the left) within a given driving time (or distance). Similarly, all road links from which the given location (2nd polygon from left) can be reached within a given driving time (or distance). The rightmost polygon in the figure shows that the main purpose is map display, because it is not guaranteed that each link covered by the spanning polygon can actually be reached. The red link outlines a motorway with exits on both ends but not within the isoline polygon. A car driving on this motorway cannot reach the location within the time/distance limit. offers accuracy on link level.
A Isoline along a Route is a buffer around a route path. This buffer covers either of following:
• The set of links that are either on the route path or can be reached by a detour of less than N seconds from the route.
• The set of links that are either on the route path or can be reached by a detour of less than N meters from the route.
• The set of custom geometries that are either on (attached to a link of) the route path or (attached to a link that) can be reached by a detour of less than N seconds from the route.
• The set of custom geometries that are either on (attached to a link of) the route path or (attached to a link that) can be reached by a detour of less than N meters from the route.
The detour is measured from the exit on the route to the center of the link. The time/distacne/cost to return onto the route is disregarded. The idea is, that this function is a first step, followed by a second step to select links/POIs and a third step to compute the final route.
Isolines along a Route are accurate on link level, see left part of the figure. The right part of the figure shows using Isolines along a Route to get a link-level-accurate version of the Isoline function: Define a very short route (almost a point) around the location.
WSE Pickup along Route identifies which optional way points along a route are worth being met. It optimizes the overall route driving cost, including cost per kilometer (aka driver cost) and the cost per hour (aka vehicle cost) including all detours to pickup and drop off goods or persons. The figure shows an example: Is it worthwhile to pickup one of the persons (or both) on my route from (0) to (1)? They want to be picked up where the face is shown and dropped off at where the reward \$ is shown.