I also get this occaisionally and I put it it down to road surface/camber

 

Don't take it to a dealer, it will probably pull to the left, unless you are braking.

 

I often get a tramlining effect when coming to halt on worn roads - I guess it is due to the nature of the fat tyres that fit into the hollows left by the trucks.

 

Mine does exactly the same as yours David, notice it most when pulling up at certain sets of traffic lights, the ones before the joining the A40 in Denham seem to be the worst. As it only does it at certain sets I just put it down to read surface, and took a look at the surface there and in is definitely not flat.

As it doesn't do it all the time there isn't much point taking it to the dealers as they almost definitely wont find anything wrong.

All my tyre pressures are correct and it doesn

 

Something that has not been mentioned yet is shock absorbers, if one has failed then this can cause a pull under braking.

- Frisky.