Geographic Concepts

Why Doesn't My GPS Simulator Automatically Follow Roads?

One of the most common surprises when first using a GPS route simulator is observing straight-line movement between plotted waypoints. This guide demystifies the fundamental boundary between geographic satellite coordinates and map-matching algorithms.

1. GPS Satellites Have No Concept of Roads

Physical GNSS satellites orbiting 20,000 kilometers in space transmit radio signals encoding time and orbital ephemeris. A GPS receiver processes these signals to calculate an exact point on Earth's ellipsoidal surface:

Latitude: 37.774929° N  |  Longitude: -122.419416° W  |  Altitude: 15.2 m

Satellites do not know what asphalt is. They have no concept of lanes, one-way streets, intersections, bridges, or speed limits. Roads exist solely as visual vector layers drawn on top of map databases (like OpenStreetMap or Google Maps).

Simulator Physics

2. Straight-Line Waypoint Movement

In Mockery Controller, routes are modeled as an ordered sequence of geographic coordinates:

// Straight-Line Vector Path
Waypoint_A ──────────── [● Vehicle] ────────────> Waypoint_B

The vehicle travels directly along the geodesic arc from point A to point B at your chosen velocity (e.g. 50 km/h).

To simulate realistic street driving with Mockery Controller, you simply click intermediate waypoints along the street corridor (e.g. at highway ramps or intersections):

Start_A ──> Turn_Corner_B ──> Highway_Onramp_C ──> Destination_D

3. How Navigation Apps Perform "Road Snapping"

Why Google Maps or Waze seems to snap your simulated vehicle onto streets.

If Mockery produces raw straight-line coordinates, why does your vehicle icon in Google Maps often appear to "stick" perfectly to the road?

The answer is client-side map-matching:

The Map-Matching Algorithm

Navigation apps know that physical GPS signals drift by 5 to 15 meters due to buildings and trees. If the app displayed raw coordinates literally, your car icon would constantly jump onto sidewalks and into buildings.

Centerline Projection

To create a polished user experience, the navigation app projects incoming coordinates onto the nearest road vector in its database. If your simulated point is within ~25 meters of a road, the app draws you right on that road's centerline.

Important Takeaway: Mockery does not snap coordinates to roads. The consuming application (Google Maps, Uber, etc.) performs the map-matching. If your simulated route veers 100 meters across open fields, the navigation app will eventually break its road lock and show you off-road.

Plot Your First Custom Route

Open Mockery Controller and click to plot straight-line waypoints along any highway, city street, or rural corridor.