Understanding logistics post-collapse
To get from the origin point to the end point, a vehicle must have fuel. It's assumed that the vehicle has a payload at the origin point, but in a collapse what's equally likely is that the payload may alter from intermediate zone to intermediate zone to the end point.
Think about it this way, the most expensive way to travel and deliver is to drive to a place, drop off the material/people, then drive back with nothing. What's more likely to happen is a teamster (an old term for a person who with draft animals made deliveries) will pick up and attempt to make deliveries all along the way in hops and attempting for a full payload whenever possible. This means to get from one coast to another coast could take a long time, because to drive straight through will mean lost wages unless paid for speed.
Things are moved today based upon anticipated inventories calculated by consumer use. This makes things flow quickly. In a post-collapse, there won't be any means of doing that. This implies data collection from consumer patterns coupled with computer modeling software and wise administration, all of which may be chaotic or non-existent.
For a vehicle to move, there must be security to get from one intermediate area to another. Since the payload contains valuables, it can be hijacked. In a collapse, any payload moving means it contains valuables, or else it wouldn't be moving. This greatly increases the cost because protection is needed. To get there requires fuel, so vehicles in a post-collapse may ride along side fuel tanker vehicles which increases the cost of transportation too.
Bugging out people are attempting to move from their insecure zone to a secure zone. They have a radius of fuel based upon driving conditions, weather, bathroom breaks, mechanical failure(flats, overheating), getting lost from diversions, etc.
When one is bugging out on the East Coast with very high population density, the concentration of bugging out people is also likely to be high. There will be a high demand for fuel and no resupply just as we saw in Hurricane Sandy. Because fuel delivery trucks also need fuel to drive there, one can't expect to get very much fuel on the East Coast.
Such departures guarantee mechanical breakdown from fleeing people as well as stranded vehicles from lack of fuel. In Winter this could be deadly from exposure to low temperatures and feral people.
Traditional preparedness doctrine has stated that the most likely safe zones are based upon higher temperature for growing season length in the South versus lower population density in the West. Most people will also come to the same conclusion and will head in those directions to some degree.
Those on the East Coast may attempt to head to Maine with low population density and natural resources. There's salt there too along the coastlines. There's very high amounts of game and fishing. Some Canadians may even head there as it's not atypical for Canadians to travel to Maine for vacation.
If you're along the East Coast, heading from one urban area to another intermediate urban area to refuel, may simply be impossible for lack of fuel and security. The only way would be to take secondary roads and still there will be issues as the collapse deepens. Narrower roads make for better ambushes, don't they?
It isn't legal to carry firearms from one state to another unless they are unloaded and you have special licenses. Each state has specific laws. Much of that could be either loosey-goosey depending upon lack of security, or it could be STRICTLY ENFORCED by security zones. During Hurricane Katrina, firearms were taken away, and in the mass confusion snap command decisions may end up disarming people driving through and that is a worrisome issue.
A governor may close the inlets to their area based upon a reduction of new people. It depends upon concern about a lot of unknown elements. They probably desire for many people to leave who are not critical infrastructure personnel with high skill level. If you fit into that category, you may not be allowed to leave in times of martial law.
Bugging in or bugging out folks need to think about whether hunkering down is a good idea based upon complex criteria. Security, supply chains, and utilities are the main issues for urban zones. Bugging out folks need to imagine going where no one is going, such that they have fuel and security to achieve their goals.
At some point of bugging out, a vehicle change to a canoe or watercraft of some sort is a logical means to putting many miles between you and these issues.
At some point, being on foot with greatly reduced supplies will be a logical aspect of continuing your journey. Your vehicle may be waved down by people looking like security, and then taken from you. You may only have what little you can carry or nothing at all. People will be stealing gas and supplies from crippled vehicles. See previous posts about fuel siphoning.
The timing of the departure means being prescient to the point of being prophetic. You have to read the security signs, plan a logical and achievable logistics goal based upon dynamic circumstances, then go suddenly as they change.
It's entirely possible that your end point may change because it's not realistic to get there. I guarantee you won't get there without many skills and supplies that you haven't considered.