Downs–Thomson - “the equilibrium speed of car traffic on a road network is determined by the average door-to-door speed of equivalent journeys taken by public transport.”
Excellent analysis. As a mobility consultant, I always emphasize that traffic congestion is a matter of thresholds, not linear growth. The math is clear: a 5-10% reduction in volume isn't just a minor tweak; it’s the difference between a functional city and total gridlock. From the infrastructure and parking perspective, public transit isn't the 'enemy' of the car—it's its life support system. It filters out the trips that shouldn't be on the road, leaving space for essential mobility
Buses clearly CAN reduce congestion. But exaggerating the extent doesn't help your case.
"... one bus can hold 40 or 50 people, replacing that many cars"
Not true. Firstly, some cars have more than one person in them. (In the UK, average ridership is around 1.6: although in rush hours that would certainly be lower, it will be well above 1.0).
Secondly, the bus only averages 40-50 people who would otherwise be in cars if all of those users live within walking distance of the bus depot, and everyone travels the whole route to the same stop in the centre of town/city. More normally, usage builds towards the centre. So whilst there might be 40-50 passengers as the bus approaches the town/city centre, the average across the length of the route might be only 20-30.
Thirdly, you need to make some allowance for the fact that the bus does not park up in town and wait for those commuters to return home in the evening. It typically heads back out to the suburbs, very lightly loaded, to pick up the next load of passengers. From an environmental point of view, you need to weigh those near-dead miles just as heavily as for the with-the-flow miles. If you are only concerned with congestion levels, then they won't be so much of a concern - but they won't have zero impact. Near-empty buses running against the flow will contribute to congestion around one-way systems, for example.
I live in Southern California, home of too many cars and too few alternatives. But this makes perfect sense to me. In addition to your very good points, the roads are filled with people who don’t like driving, who are uncomfortable driving, who shouldn’t be driving because they are impaired or feeling sick or upset. In car-centric areas they have no choice. Give them (us) options!
I met a lady from the USA awhile back who was saying "Why should my taxes fund public schools? I don't have kids!" I remember thinking so other people's kids grow up to be doctors, nurses, engineers or some other fulfilling useful career you rely on and not criminals breaking into your house.
In much the same way, if people can't afford to travel to work what do you think will happen?
I'm persuded that more frequent service with more, smaller buses though more costly can over time do a lot to increase use of buses.
Downs–Thomson - “the equilibrium speed of car traffic on a road network is determined by the average door-to-door speed of equivalent journeys taken by public transport.”
Excellent analysis. As a mobility consultant, I always emphasize that traffic congestion is a matter of thresholds, not linear growth. The math is clear: a 5-10% reduction in volume isn't just a minor tweak; it’s the difference between a functional city and total gridlock. From the infrastructure and parking perspective, public transit isn't the 'enemy' of the car—it's its life support system. It filters out the trips that shouldn't be on the road, leaving space for essential mobility
Buses clearly CAN reduce congestion. But exaggerating the extent doesn't help your case.
"... one bus can hold 40 or 50 people, replacing that many cars"
Not true. Firstly, some cars have more than one person in them. (In the UK, average ridership is around 1.6: although in rush hours that would certainly be lower, it will be well above 1.0).
Secondly, the bus only averages 40-50 people who would otherwise be in cars if all of those users live within walking distance of the bus depot, and everyone travels the whole route to the same stop in the centre of town/city. More normally, usage builds towards the centre. So whilst there might be 40-50 passengers as the bus approaches the town/city centre, the average across the length of the route might be only 20-30.
Thirdly, you need to make some allowance for the fact that the bus does not park up in town and wait for those commuters to return home in the evening. It typically heads back out to the suburbs, very lightly loaded, to pick up the next load of passengers. From an environmental point of view, you need to weigh those near-dead miles just as heavily as for the with-the-flow miles. If you are only concerned with congestion levels, then they won't be so much of a concern - but they won't have zero impact. Near-empty buses running against the flow will contribute to congestion around one-way systems, for example.
I live in Southern California, home of too many cars and too few alternatives. But this makes perfect sense to me. In addition to your very good points, the roads are filled with people who don’t like driving, who are uncomfortable driving, who shouldn’t be driving because they are impaired or feeling sick or upset. In car-centric areas they have no choice. Give them (us) options!
I met a lady from the USA awhile back who was saying "Why should my taxes fund public schools? I don't have kids!" I remember thinking so other people's kids grow up to be doctors, nurses, engineers or some other fulfilling useful career you rely on and not criminals breaking into your house.
In much the same way, if people can't afford to travel to work what do you think will happen?
Transit is more than transport.