Continuous Convoys & En Route Sequencing

One of the major tradeoffs in high speed mass transportation systems is the speed of an express vs. the convenience of the local with many intermediate stops.

My innovation of Continuous Convoys & En Route Sequencing give us both: each person receives non-stop service from where they get on to where they get off.

The basic idea of a Continuous Convoy is simple: a Convoy goes racing along at full speed. As the Convoy approaches a station, the passengers and items boarding at that station are already aboard a Convoy Vehicle, which accelerates and let’s the Convoy catch up, so it is at the front of the Convoy. As the Convoy approaches a station, the Convoy Vehicle at the end of the Convoy has all the passengers and items for the next station, detaches prior to the next station, decelerates and stops at the station. Passengers and items leave the vehicle, and the cycle continues.

The basic idea of En Route Sorting is also simple: after your Convoy Vehicle attaches at the front of the Convoy, you need to move to the Convoy Vehicle which will stop at your destination station.

Things get a little complicated if the Convoy Vehicle that will stop at your station hasn’t joined the Convoy yet; then you will need to move while the Convoy is in motion to get to your desired Convoy Vehicle.

This is where it helps if you are already riding an Autonomous Vehicle which is riding Nested in the Convoy Vehicle, because then your Autonomous Vehicle can take care of moving you to the proper Convoy Vehicle without your having to move or even think about it. Thing get even better if you need to change from one Convoy to another, because your Autonomous Vehicle an take care of that transfer for you too.

Sorting things en route is an old idea, for example, from 1864-1977, the Railway Mail Service used clerks on board moving trains to sort and process mail, speeding delivery.

You get the full benefit of the speed of the Convoy, with only one acceleration and deceleration at the beginning and end. This also saves a lot of energy, because only the Convoy Vehicle with the people and items destined for a station stops there. Because the kinetic energy is proportional to the square of the velocity (E=Mv²), this energy becomes important the higher the speed of the Convoy. Another benefit is that the energy regained with regenerative braking from the Convoy Vehicle as it approaches a station can be transmitted through the electric feed to power the acceleration of the nearby Convoy Vehicle just leaving the station.

This approach can be used with existing trains if the cars are individually powered. So the ideas can have immediate benefits. For existing trains, Intercity rail travel is 27% more efficient than Commuter rail travel (2,271 vs. 2,897 BTU/passenger mile, http://cta.ornl.gov/data/chapter2.shtml table 2.12).

Note the “station” does not have to be stationary – it might be another Autonomous Vehicle connecting to another route or to another mode of transportation (including faster or slower). This allows moving from one Convoy to another without stopping, and thus presages a network of Autonomous-Ways for Autonomous Vehicles, as described under A-Ways.

For a detailed example, including graphics of passengers and Convoy Vehicles, see Continuous Convoys and EnRoute Sequencing, How Many Vehicles in a Continuous Convoy?. Another analysis is in Continuous Convoys for NYC Subways.

The example shown there is for travel by the existing railroad from Long Branch, NJ to New York City. 

Here are some further results of the time savings possible with Continuous Convoys and En Route Sequencing for that route. The calculations show it is faster to drive than to take even the Express  train (10 stops). But even at only 60 mph, the Convoy trip is 13 minutes faster that a car (and that’s assuming no traffic congestion, lots of luck), and 25 minutes faster than the Express.

Ironically, making the train go faster doesn’t help that much because it spends so much time loading, unloading, accelerating and decelerating that it doesn’t gain much advantage from the theoretical maximum speed. The Continuous Convoy does take full advantage of the speed, so an Acela-like speed of 120 mph gets your there in 30 minutes, and with a bullet train speed of 240 mph, you are there in 16 minutes, vs. 55 minutes for the Express.

Thus I believe Continuous Convoys and En Route Sequencing can have near-term results in getting people out of inefficient cars and into mass transit.

The train trip distance from Long Branch to New York City is 55 miles, with 10 or 18 intermediate stops for the Train, and no intermediate stops for the Convoy. Driving time is per Google Maps, and traffic conditions will add to the time.  I’ve included different maximum speeds for the Train and the Convoy: note in the 240 mph case, the Train can only accelerate to 200 mph before it has to slow for the next stop, assuming the stops are evenly spaced; including all 18 intermediate stops, the Train reaches a maximum speed of only 155 mph. For those interested in the assumptions:  0.1 g acceleration and 120 second stop at each station to load and unload.

Another analysis is in Continuous Convoys for NYC Subways.

I spent many days trying to think of how to use existing tracks and stations, that is the existing infrastructure, to achieve a much faster commute. Finally I came up with Continuous Convoys and En Route Sequencing.

Later I’ll present additional ideas to deal with the realities of the Long Branch-to-NYC train: the tracks aren’t up to the higher speeds, there are a lot of at-grade crossings, and other trains use the same tracks.

But you can apply the same ideas to Amtrak trains to achieve similar gains. For example, I wanted to take the Acela from Metro Park, NJ station to the New Carrolton, MD station, but none made both stops. Of course we need new vehicles: each Vehicle needs to operate autonomously, with its own power, so we still have some work to do. More on that later.

Next we'll talk about Autonomous-Ways or A-Ways.