I'd guess that until PTC becomes standard across the country, new lines may be deployed with out it. The lack of PTC certainly doesn't stop them from running tr

I'd guess that until PTC becomes standard across the country, new lines may be deployed with out it. The lack of PTC certainly doesn't stop them from running trains on pre-existing lines today. I've spent almost the last decade involved with designing and implementing the messaging system behind PTC. Every one of these disasters makes me wish it was deployed everywhere. But for better or worse, railroads are incredibly change and risk intolerant. Everything goes through extensive testing before being rolled out into the field, which can add several years to any rollout plan.