The purpose of distance to nearest design rule is to inform the user about distance to potential constraints or GIS features of interest from every point along the route.

This design rule requires little configuration, it just has to be enables. There are three of these design rules: one for Constraints dataset, one for Environmental dataset and another for Linear Feature dataset. The design rule will return distance-to-nearest for all features included in relevant dataset.

The design rule identifies all individual features within layers and extracts their edges. This provides the User with the minimum distance between the route point and the polygon, not the minimum distance to the polygon centre.

Optioneer represents options as centerlines with discrete, interconnected points (sampled around every 30 meters). Since we want the user to know distance-to-nearest feature at every point of the route, the calculation is done on a per point basis.

Distance to nearest is recorded on a per-layer basis. As a result, for every point on the route, Optioneer will return information along the lines of 'at point 200, the distance to nearest feature of layer A is 230m, the distance to nearest feature of layer B is 4500m etc.'

The data resulting from this operation is later available to the user via Optioneer UI, in the Vertical Profile Chart /Composition Chart/Distance'.

^^ replace with Video: https://www.loom.com/share/9da3288494064a5aa092efbb7ed96b24

As you can see above, two adjacent points often have different features that are 'nearest'. Naturally, it would be good for the user to know when that change occurs. Luckily, Optioneer also identifies the ID of feature that is nearest at a given point.

This functionality has to be explicitly enabled in design rule configuration (under 'Model' tab). There is only one parameter in this design rule - 'Select whether to return IDs of the nearest features'. Set this to True or 1 for this functionality to be enabled.

This functionality operates to similarly to everything described above, but instead of returning the 'distance between a point and nearest feature in a GIS dataset', it returns 'the ID of the feature which is nearest to the point'.

This ID is not currently very informative, but it clearly indicates where the 'nearest feature' changes - see below. Feature changes anytime that the histogram value changes.

NB: All layers are stacked on the same histogram. Other layers might move the layer you are interested in up or down, always check the values on the tooltip (or remove other layers).

Functionality 3: Getting the position index where distance to nearest is the lowest.

This is additional functionality which complements the previous two. Optioneer returns a position of the point along the option route where the distance-to-nearest feature within a given GIS layer is the lowest.

Position index means which point along the route the minimum distance is found at. In the example below, the nearest SPA feature is found at the 3rd point of the route, counting from the starting point. This helps locate the minimum, but it doesn't give a chainage (to get approximate chainage, multiply the position by 30m).

Datasets required

Input parameters

Output parameters