Focus Modes While Railfanning

[High Hood]

I was wondering which focusing techniques people predominately use while railfanning. Personally, I used to use continuous and follow the train as it travelled, but I’ve made the switch over to prefocusing and keeping still. I’m definitely interested in hearing how others get their shots. 

[MK]

What camera are you using?  The higher end ones tend to track and focus better in Continuous mode.  Also slightly depends on what lens you are using (I'm assuming DSLR here).  Some are better at faster focusing.

If your camera is neither of the above your method of pre-focusing to a certain spot certainly work too.

I have a Nikon D500, probably the best DX sports camera out there and is built for tracking moving objects.  I use Continuous mode using what Nikon calls D25.  There are 25 focus points surrounding the main focus point aiding in focus determination.  Let's just say if it's not in focus it's me and not the camera.  And able to do 10 fps out of the box helps too.   

[High Hood]

I've been using a D3100. I'm hoping to switch over to the Z6 after I can get a new job. What caused me to switch my way of focusing was my autofocus kept getting tripped up by bright locomotive headlights. Not a problem with prefocusing!