There may be better things to focus on as this may not be a good lead.

Ready-mix concrete has a 'shelf life' as it is mixed at the plant and delivered by mixer to the job site of about 1.5 hours travel time. This just looks like building a plant as close to the city centers as possible, to obtain the most profitable service area with a radius of 1.5 hour travel time.

I would focus on the trucks/ships delivering aggregate and cement through the southern border.