But is there any need for the pods to touch or even be closer than a few meters other than minimizing air resistance? For that matter, I'm not at all sure how air resistance would work in a Loop tunnel. Assuming 7 m pods, max acceleration 1 m/s2, line length 1609 m (1 mile), 20 pods per platoon, 100 msec between pods, and a launch spacing of 30 sec per platoon. That gives 11 seconds between platoons and a maximum of 4 m between pods. The line capacity is over 38000 passengers per hour assuming full pods with 16 people per pod, and a travel time of 80 seconds, max speed of 40 m/s (90 mph). Unfortunately this also points out a pretty serious problem with at least my understanding of how the Loop system would work. For the example above, the pods would never reach full speed because they can't accelerate enough. They'd spend half the time accelerating and half decelerating, which means they couldn't merge into a full speed bore. At 1 m/s2 it takes about 2250 m (1.4 miles) and 67 sec to get to 67 m/sec (150 mph) and the same to stop. I think there would have to be a set of different speed bores with interconnects so multiple lines could share the same "trunks". With a max speed of 22 m/sec (50 mph), about what current subways use, it would take 250 m to accelerate (22 sec), so the minimum length would be 500 m (.3 miles). The total time for the above example would still be only 94 sec and the max pod to pod spacing would be just over 2 m.