Thoreau speed of cars, bikes and walking

There's an interesting discussion here about Thoreau speed:

In Walden, Thoreau proposed a modification of the traditional formula for calculating speed. Instead of merely dividing the distance traveled by the time it took to cross it, Thoreau proposed reckoning also the cost of the ticket.

So, after some assumptions and calculations, where are we left?

Kifer has also assessed the costs and the Thoreau speed of bicycles, into the bargain. He estimates the Thoreau speed of cars as between 4.8 and 14.4 miles per hour, and the Thoreau speed of bicycles as between 8.9 and 14.8 miles per hour. Though beaten to the punch, I'm posting anyway, because my sources and method are different yet I end up confirming Kifer's conclusion: When costs are factored in, cars are not faster than bikes and only twice as fast as walking.