Tilt the road and part of the normal force starts aiming at the centre of the bend. At one speed the tilt does the whole job on its own. Move away from it and the friction readout comes off zero — and changes sign.
Negative, so friction acts up the slope. The tyres have 0.60 to give.
Safe speed band friction included
Minimum11.7 m/s
Maximum33.8 m/s
Anywhere inside this band the tyres can hold the car on the bank.
Centripetal acceleration a = v² / r
3.33 m/s²
0.340 g · the sideways pull the road must supply
Status
Slides down
Slower than the design speed, so the car tends to slide down the bank and friction points up the slope to hold it.
Banking angle θ20.0°
Radius r120 m
Speed v20.0 m/s
Static friction μs0.60
Gravity is fixed at g = 9.81 m/s² — it is not a control here. The angle is set in degrees and converted to radians internally. Mass has no slider because it cancels out of every speed on this panel.
Try this: press Set design speed and the friction readout drops to exactly zero. Now nudge the speed slider one step either way and watch the sign flip.