Complaint 1:Involuntary direction changes outside of the drivers command. 2:Unpredictable changes of direction on different road surfaces. What's going on? Tramlining is a relatively recent complaint due to... 1: The road condition 2: The low profile tyre 3: The tyre 1: Motorway troths act like rails with walls 2: Contact patch deviations and sidewall communication 3: Some tyres are designed to require yaw in order to deviate the current line of travel. To the point.... It's a combination of factors but really simple to understand. Over the years wheels have become bigger/ tyres wider, in order to allow this the tyres sidewall had to become smaller. To allow for the smaller sidewall it has to be stronger in order to cope with road irregularity's ( pothole's and alike ) but deviations in the contact patch due to the road condition can no longer be lost between the patch and the wheel due to the reinforced sidewall..... There's no lateral flex. A deviation from the contact patch directly communicates to the rim and steers the car. Tyres 1: Symmetrical tread pattern is less susceptible to tramlining 2: Directional even less, but prone to other issues on the MB 3: Asymmetrical tyres ( MO ) i might add are the worst but fall way short of the RFT ( run flat tyre ) What to do? You need to minimize the damage, here are the options 1: Be wise on your tyre choice 2: Manipulate those tyre pressures 3: Have the front "toe tendency set? To explain 1: Done that see above 2: The suggested tyre pressures are just that "suggested", within reason by changing the pressure you can change the flexibility of the tyre sidewall, this in turn changes the "communication". 3: As the suspension migrates through bump and droop the "toe angle" ( tracking ) moves, it might go from a bit in to a Lot out. Finding the migration values and setting the toe position to it mid-point will minimize tramelining. A problem Non of the above solutions will work on every car, a combination of solutions would need to be used for each example. Well that all reads depressing.... It's not! You have the option on tyre make, you have the option of manipulating the tyre pressure and you know know about "toe migration on bump/ droop".