I think they are on both sides of the trucks. I was watching a driver in his rearview mirror as I ducked past a cement truck on the outside (he was almost stationary, plenty of space and options for bailing out if he moved). As soon as I got to his rear right corner, he snapped a glance in his rearview mirror straight at me.
Remember thinking that he knew I was there. No audible alerts for me though.
I think they are on both sides of the trucks. I was watching a driver in his rearview mirror as I ducked past a cement truck on the outside (he was almost stationary, plenty of space and options for bailing out if he moved). As soon as I got to his rear right corner, he snapped a glance in his rearview mirror straight at me.
Remember thinking that he knew I was there. No audible alerts for me though.
Pure speculation though.