wrong speed limit detected
MBWorld Fanatic!
Joined: Oct 2009
Posts: 7,029
Likes: 2,205
From: Colorado
'21 AMG53 wDPP & ARC, 19 GLC300 - Former-03 C240,2 ML BlueTecs,20 GLE450 E-ABC,15 Cayenne D,17 Macan
Senior Member
Joined: May 2019
Posts: 331
Likes: 119
From: Tennessee
2015 MB S550 & 2020 MB GLS 450
My thought is that with the "unless otherwise posted" below the speed limit sign, the systems does not acknowledge it as a speed limit sign. I have seen speed limit signs in yellow or orange that are in construction zones not get recognized, and speed limit signs on a post with other signs that did not get recognized. Seems that if the system coordinated with NAV, that temporary construction zones might be ignored.
I like the system, particularly in construction zones. Sometimes I will use the pedal to speed up and reset the cruise, and sometimes just let the vehicle speed up when it sees the next higher speed limit sign.
The only time it has been a pain is, as mentioned in one of the first posts, when I go thru Georgia interstates the system detects the 40 mph minimum sign as the limit and wants to slow down. I just look out for those and accelerate slightly which suspends the system until I pass the sign.
I like the system, particularly in construction zones. Sometimes I will use the pedal to speed up and reset the cruise, and sometimes just let the vehicle speed up when it sees the next higher speed limit sign.
The only time it has been a pain is, as mentioned in one of the first posts, when I go thru Georgia interstates the system detects the 40 mph minimum sign as the limit and wants to slow down. I just look out for those and accelerate slightly which suspends the system until I pass the sign.
Out Of Control!!
Joined: Nov 2018
Posts: 11,479
Likes: 5,359
From: San Francisco Bay Area
2019 C63CS
My thought is that with the "unless otherwise posted" below the speed limit sign, the systems does not acknowledge it as a speed limit sign. I have seen speed limit signs in yellow or orange that are in construction zones not get recognized, and speed limit signs on a post with other signs that did not get recognized. Seems that if the system coordinated with NAV, that temporary construction zones might be ignored.
I like the system, particularly in construction zones. Sometimes I will use the pedal to speed up and reset the cruise, and sometimes just let the vehicle speed up when it sees the next higher speed limit sign.
The only time it has been a pain is, as mentioned in one of the first posts, when I go thru Georgia interstates the system detects the 40 mph minimum sign as the limit and wants to slow down. I just look out for those and accelerate slightly which suspends the system until I pass the sign.
I like the system, particularly in construction zones. Sometimes I will use the pedal to speed up and reset the cruise, and sometimes just let the vehicle speed up when it sees the next higher speed limit sign.
The only time it has been a pain is, as mentioned in one of the first posts, when I go thru Georgia interstates the system detects the 40 mph minimum sign as the limit and wants to slow down. I just look out for those and accelerate slightly which suspends the system until I pass the sign.
- It uses your position and the map to determine which road you are actually on to figure out applicable speed limits. This is particularly useful with frontage roads. It uses the NAV to figure out if you are driving on the highway or the adjacent frontage road, so that when it detects the speed limit on the frontage road it will ignore it if you are on the highway. However, this doesn't always work due to accuracy degradation of GPS, so it could think that you are driving on the frontage road and show the wrong speed limit. Plenty of examples that people have reported where the car picked the frontage road speed limit instead of the highway speed limit.
- It uses the maps for national speed limits. If it doesn't detect a speed limit sign for some time, then it falls back to what the national speed limit is for the type of road you are on, or the speed limit stored for the current road in the map data.
