Join and exit A3 

Is this part of a test route? If so, which one? Do Morden Test Routes go on A3? Thank you for videos. Big help!

independent driving following signs 0:03 c.london is on the left, after cycle lane 0:31 joining dual carriageway from SLIP ROAD 50MPH SPEED LIMIT (match speed) 0:48 signal right when safe to do so 1:22 msm exit on left SPEED LIMIT CHANGES TO 40MPH 1:45 msm move to left lane 2:26 at next traffic light turn right. When road gets wider position to the right side of your dual carriageway 2:46 msm move right to filter lane 4:20 20MPH

Is the speed limit on the slip road 30 or 40