1. Coming up to a 4-way stop. I take a position in my lane for a left turn (two or three feet to the right of the center of the road) and this happens:
2. Same intersection, I'm turning left, and this happens:
The green car has stopped, because I arrived at the intersection first. As I check, I notice the purple car approaching from my right, slowing (I assume for the stop). But instead of stopping, he moves into his left lane (the oncoming traffic lane) intending to turn into my lane (again, the oncoming traffic lane). He stops at the second position in the diagram because he can't comfortably get past me (he could have squeezed by but he chickened out at the last second). I proceed to take my turn, shaking my head in disbelief. This happened this morning.
Both situations seem to me to be hazardous. Is there anything I can do to make these scenarios less likely, without undermining my ability to counter more likely problems?
For example, to counter problem 1, I could simply take a wider turn, but that would put me in the oncoming traffic lane longer, which is surely more dangerous for me. It would also presumably put me in danger from a car behind me trying to get by me on the right. As things stand with what I do now, it seems to me that the motorist takes the biggest risk.
To counter problem 2, I could take a more central position in my lane, which would more effectively counter the guy attempting to cut the corner, but which would confuse road users as to what I intend to do (note also that my approach to this intersection is downhill, so signalling is difficult as I need to be using both brakes coming to the stop). As things stand, I did prevent the car from cutting the corner, but I'm not sure if a more aggressive driver would have been so easily dissuaded.
The intersection is the corner of Lanark Way and Lorain Avenue in Silver Spring. I'm going south on Lorain.