If you are referring to having the device alert you if you are going over the speed limit, I don't think any of the Nuvi models support this. Most of the newer models show a speed limit sign on the map, but they have no option for alerting you if you go over that.
None of the Nuvi's do speed checks
If you are referring to having the device alert you if you are going over the speed limit, I don't think any of the Nuvi models support this. Most of the newer models show a speed limit sign on the map, but they have no option for alerting you if you go over that.