Route Cost Analysis
Definition
A GIS operation using a friction or cost surface (based on slope, vegetation, and path availability) to model the least-effort path between two points. Applied in search management to estimate how far from an access point a perpetrator could realistically carry a body in a given time.
- Domain
- GIS-based search management
- Uses
- Friction or cost surface (slope, vegetation, path availability)
- Models
- Least-effort path between two points
- Application
- Estimate how far a body could be carried from an access point in a given time
Common questions
What inputs does a friction surface typically combine to model realistic travel effort?+
It layers factors such as terrain slope, vegetation density, ground cover type, and the presence of trails or roads into a single raster, where each cell's value represents the relative effort required to cross it.
How does route cost analysis narrow a search area in practice?+
By modelling a maximum plausible travel time or distance from a known access point across the cost surface, investigators can generate a bounded probability zone that prioritises where ground or canine search teams deploy first, rather than searching an unweighted radius.
What is a key limitation of route cost analysis for predicting an offender's actual path?+
It models the theoretically least-effort route based on terrain alone and does not account for the offender's actual knowledge of the area, time pressure, or deliberate avoidance of the most obvious path, so it produces a probability estimate rather than a confirmed route.
Related terms
- Chain of Custody (Digital)
- The documented record of who created, processed, stored, and accessed a digital file from its acquisition to its presentation in court. For...
- Coordinate Reference System (CRS)
- The mathematical framework defining how coordinates relate to real-world positions on the Earth's surface. All layers in a forensic GIS must share...
- Georeferencing
- The process of assigning real-world coordinates to a raster image or survey grid using known control points. A ground-penetrating radar grid, for...
- Search Coverage Layer
- A polygon or raster attribute layer recording which portions of the search area have been surveyed, the method used, and the outcome....
- Weighted Overlay
- A GIS operation that combines multiple raster layers into a single output by multiplying each layer by a weight and summing the...