So here it's really dependent on how the parking lot is set up but there are normally clear lane markers. I'd probably be contacting the powers that be that can control that aspect to notify the lane markers really need to be added in your area OP.
There will be times where there is only room for one lane
to a point and then it widens up to wear people are able to split off and form two lanes.
For example here is a popular one:
View attachment 367492
The drive thru lane is 1 lane marked to a point. Cars that try to get out and get into the second lane too early would actually be causing traffic problems because they block access to those parking, getting out of their parking spot and leaving the parking lot. It is designed to where car split off into the two sides just closer to the ordering machines and before that it's 1 lane.
Here's another one in our area:
View attachment 367493
And another one:
View attachment 367495
Notice how this one there are 2 drive-thru lanes to begin with which then feed directly to the assigned ordering machine.
People are familiar with two lanes and alternate orders here though so there's rarely been a problem at least in my personal experience.
So really IMO it's going to be dependent on each and every location and how they are set up. Some locations have a lot more room to have two lanes further back and some don't thus they have 1 line until it gets closer and splits.
I should also note that things related to drive-thru lanes are typically in yellow road paint whereas white paint is typically for normal traffic.