Not seeing any news articles.
Same here.
Strange if this is intentional and strange if it isn't. Something is off here. TNT won't explode from fire. It needs a primer to set it off so a Dynamite explosion would need to be intentional but if this was intentional, why choose an open area like this? If the goal is to do damage, there are a lot of places to cause more damage than out in the open on a highway.
And that crater and debris field is definitely a detonating explosive. The only thing I know of that will detonate like that without needing a primer and is readily available is acetylene. My guess is a welding tank truck.