Comment by jasode | Hacker News Reader

Comment by jasode | Hacker News Reader

Parent Full thread

>And shifting traffic from personal cars to buses would make mobility much more efficient. Because in a bus, 30 people can cross a crossing so much faster than in a line of 30 individual cars. [...] I would expect travel to speed up when we move from cars to buses. Look at what cars do most of the time. Waiting at crossings, slowing down for crossings, accelerating after passing a crossing. I have not measured it yet, but I would expect buses that carry 20 passengers each to accelerate that by a factor of 10 or so.

Your math is leaving out a lot of other waiting periods which makes it seem like buses save time over cars. Your focus on crossing intersections is distorting the calculations.

Yes, 1 bus can move 30 passengers through a traffic light is faster than 30 individual cars but you have to offset that savings with extra wait times in other places:

+ add additional time to travel to the bus stop

+ add additional time to wait at the bus stop because buses don't come on demand but at spaced intervals. Maybe once an hour or half hour.

+ add additional time for bus to stop at other bus stops that are not relevant to the passenger, or changing buses,

+ add additional time to account for the bus taking a longer convoluted route that deviates from the shortest path between points A and B because they have to accommodate for the bus stops and also optimize the # of buses in the fleet vs passenger counts.

+ add time to travel from the final bus stop dropoff point to travel to the final destination without the bus. Each mile of walking takes about ~20 minutes. If the bus stop is too far away from the destination office or house, then I guess the passenger can take an Uber ride? Not only does that add more time, it negates a lot of benefits of using the bus. People could use the Uber for the entire trip -- or just use their personal car.

There are scenarios where the bus is undeniably faster. Inside dense cities where they have special lanes that can bypass some gridlock. The tour buses with stops that have frequent pickup intervals that do continuous loops around cities for tourists is another example that's faster than cars.

My perspective is from living in a big city. Hamburg in Germany. Here it is like this:

    add additional time to travel to the bus stop

That is more than offset by the time and stress to find a parking place when you use a private car.

    add additional time to wait at the bus stop

I would guess the average wait time here is about 3 minutes.

    additional time for bus to stop at other bus stops

True, but decreases the more buses there are. The more buses, the less stops every bus has to do. And also decreases the better the planning via internet becomes. We have buses here in Hamburg, called "Moia" by Volkswagen, where you announce your starting and destination positions in advance, and the bus only stops where it has to.

    additional time to account for the bus taking a route
    that deviates from shortest path

True, but decreases the more buses there are. And the better we plan the routes via the internet with people announcing their route upfront.

> add additional time to wait at the bus stop because buses don't come on demand but at spaced intervals. Maybe once an hour or half hour.

I mean, this is enormously dependent on how busy the route or routes is. A once an hour route is _very_ infrequent. Every 10 minutes isn't unusual at peak times and of course multiple routes may work for you. I sometimes go for a drink with friends on the other side of the city after work; at rush hour, there's an almost continuous stream of suitable buses.

>I mean, this is enormously dependent on how busy the route or routes is. A once an hour route is _very_ infrequent.

Yes, it depends on the city. In Atlanta GA, the MARTA bus stops have 40-minute wait intervals outside of peak times. In Missoula Montana, the bus stop interval is 1 hour on Saturdays and Sundays. https://mountainline.com/your-trip/maps-schedules/

In the USA away from dense downtowns, using a public bus can be 4x the total commute time of a personal car when adding in all the extra wait times and the extra non-bus travel times to get to-and-from the bus stops. A 30-minute commute by car that takes 2 hours by public bus isn't appealing to most Americans.

The layout & logistics of American lifestyles favors the car. At any Costco parking lot, you can see soccer moms loading up the SUV with a ton of groceries and toilet paper. Trying to haul all that on a public bus would not be convenient. (The other passengers would also be annoyed by that extra baggage taking up space.) And drivers also like listening to music in their private cars.

In the USA, the more realistic consumer preference change would be replacing private personal cars with public robot driverless cars. Americans could then keep most of their lifestyle without drastic changes while the fleet of driverless cars reduces the space for parking and the pollution.

> In Atlanta GA, the MARTA bus stops have 40-minute wait intervals outside of peak times. In Missoula Montana, the bus stop interval is 1 hour on Saturdays and Sundays.

Yeah, okay, wow, that's really bad. Only place in the US I've ever used the bus was San Francisco (and its immediate surroundings), which is, I suppose, a bit of a special case, as American cities go (it was worse than the buses I'm used to in terms of frequency, but not _dramatically_ worse).

> The layout & logistics of American lifestyles favors the car.

This is true to some extent, but I would wonder how much of it is chicken-and-egg; people avoid the public transport because, as you've mentioned, it is _unusably bad_ (I wouldn't consider 1/hour acceptable except for late-night or rural services). As I understand it, in NYC, for instance, which has acceptable public transport, people _do_ use it.

> At any Costco parking lot, you can see soccer moms loading up the SUV with a ton of groceries and toilet paper. Trying to haul all that on a public bus would not be convenient.

Grocery delivery is a thing (actually, my impression is that it's less common as a first-party thing in the US; I'm not entirely sure why). And of course even in less car-dependent countries people often do use cars for _that_ sort of thing.

> And drivers also like listening to music in their private cars.

I mean, this would have made sense as a justification at one time (I think way back in the day this was actually used as a selling point by car companies), but come on, now, the walkman came out in 1979 (even before that, the transistor radio with earphone was a thing). I'm 40 and have been listening to music on public transport all my life.

Reply on news.ycombinator.com