There are many who have asked the question, whether coasting in neutral or engaging engine braking is more fuel efficient in coming to a stop. One such discussion led to the following top comments:

Engine braking. It shuts off fuel and lets the cars forwards motion turn the engine.
Coasting means you use fuel to keep the engine idling.
Next.

and

That assumes your car has deceleration fuel cut off.
But normally yeah, engine braking would technically use less fuel than idling/coasting.

Now I don’t know anything about cars but I do have a mental model of a mechanical engine. When no fuel is injected, engine braking should work by having the engine do mechanical work to compress and heat up air (then ejecting it). So RPM matters, as the higher the RPM the higher the energy absorbed per unit time.
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MBTA has these “BIG RED” high-capacity cars now, but guess what? All they did was to remove all the seats. The trouble is, this form of so-called “high capacity” doesn’t actually add much capacity. You still have to hold on to these loops or bars and there are only so many of them. The trains look more spacious though… I think they’re confusing high personal space with high capacity.

(Why do “suit” and “purple” choose to stand?)

There is a better way to add capacity and reduce crowding in the subway car, however. Make the damned seats wider! What people do right now — due to some kind of human repelling force — is to skip every other seat unless the situation is really saturated, because it’s impolite and uncomfortable to squeeze next to/in between people. So MBTA ends up with half the designed seating capacity and the overflow just stand, sometimes right next to/blocking an empty seat. Just remove one seat per row and the number of seated people may increase dramatically. This applies to classrooms and other contexts, too.

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This is interesting, this self-parking car thing. Well, it’s not completely automatic, but it is supposed to take care of the most difficult part. Now I know my driving test required a demonstration of parallel parking ability – not sure about other states, so it is natural to ask, if somebody had this car, should they turn this off for the test?

Are there existing conventions dealing with technological aid in various kinds of skills testing? I can think of some, and they generally seem to fall on the side of accepting technology, with restrictions that can sometimes be arbitrary. For example, on the SAT you could use a graphing calculator, but not one with a “QWERTY” keyboard, so a TI-89 was okay but the TI-92 was not, even though they ran the exact same firmware. Not sure if they changed this. Guess not. The College Board still appears to be living in the stone age with regard to some of these banned calculators:

• calculators with QWERTY (typewriter-like) keypads arbitrary
• calculators that contain electronic dictionaries they all do now or can
• calculators with paper tape or printers cash register? lol
• calculators that “talk” or make noise right
• calculators that require an electrical outlet haha
• etc…

That aside, the car that drives itself has got to be the most popular civilian application touted by sensor networks people. So far, most automated components of the car are not fully automated. There is always some human element in some key part of the chain, unlike in airplanes. There is some human resistance toward giving up control on this matter. The trend toward more automation may be unstoppable, though, if automation creeps in a bit at a time like this.

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