We tried Tesla’s, Cadillac’s, and Mercedes’ semi-autonomous driving systems — and the winner is clear

Autopilot has been around for longer than the other two technologies. Unlike Cadillac Super Cruise, it doesn’t read from detailed maps created by laser-radar GPS. Instead, it uses a suite of cameras, radars, and sensors to create a 360-degree view of the car.

Autopilot can, in theory, be used under many driving conditions, and because it doesn’t use Lidar, Tesla believes that it can operate in bad weather better than other systems.

The times I’ve used it, I’ve found that it works best on large freeways where traffic is moving at a consistent speed. But it can function on what I would call smaller highways and multi-lane thoroughfares, sort of like very advanced adaptive cruise control.

Currently, the system is what Tesla calls “Enhanced Autopilot” (“Full Self-Driving Capability” is on the horizon and Tesla thinks it has the right software/hardware combo to make it work). Autopilot now costs $5,000 to add when you order a vehicle, but $6,000 as a post-purchase upgrade.

Autopilot periodically prompts you to retake control, flashing a lighted ring around the instrument cluster. If you ignore the warnings, the system will eventually disable itself until you run through a charge cycle (meaning you have to pull into a charging location and plug it in, but you don’t have to fully deplete the battery).

Autopilot can change lanes and park itself without having a driver inside. It can also take itself out of a garage, and generally begin to behave like a robot chauffeur. For now, it can be used effectively in stop-go-traffic and on non-highway thoroughfares, so it works like the best adaptive-cruise-control system on the market.