May 27

Why We Need Multimodal Transportation Solutions

The private automobile is the transportation backbone of most of today’s cities. Its on-demand point-to-point service is the best option to meet the needs of the majority of urban dwellers. But for visitors to the city, who have left their cars at home, there need to be other options. Taxis or ride-hailing services are a good choice for a few trips in well-traveled areas. For more frequent trips into outlying neighborhoods, a rental car might be a better fit.

For those who cannot drive, or who have abandoned their cars because of chronic traffic congestion or inadequate parking, there must be a public transit option. Mass transit systems, such as subways or light-rail trains, have the ability to quickly move large numbers of people between widely-spaced stations. But that means that each station must serve a large area. So you need a way to move lots of people to and from those stations. This is called the “last mile problem”. (Although in many cities, it’s more like the last five miles.) To address this issue, you need a network of busses. Even then, few cities are able to provide bus stops within walking distance of most places. And neither busses nor mass-transit are economical to operate during off-peak hours.

Private cars, rental cars, taxis, ride-hailing services, mass transit, and buses each have their strengths and weaknesses. Since none of these systems alone can satisfy the full range of needs, the conventional wisdom has been that we need them all. The result is a complicated patchwork of travel modes that is difficult to navigate. And each mode must compete with the others for scarce resources.

Multimodal transportation often involves one or more transfers. To a transit planner, this may seem like a solution to a problem, but for the passenger it is a problem in need of a solution. Every transfer brings with it extra waiting, extra ticketing, and a chance of a missed connection. Given a choice, people avoid transfers wherever possible.

The advent of automated transportation changes all of this. By combining the convenience of a car with the accessibility of public transit, there’s no longer a need for multiple modes. An automated vehicle is cheaper than a taxi, and faster than a bus. It provides the same high-quality service to visitors as to residents, to the young and the old, to the poor and the disabled.

And in combination with advanced infrastructure, such as above-ground, dedicated guideways, self-driving vehicles can also rival the capacity of mass-transit. And elevated guideways have a smaller footprint than any conventional transport.

In a multimodal system, you have a backup if one system is out of service. But Automated Transit Networks can be designed to have no single point of failure, so they can continue to operate even after a breakdown of a vehicle or guideway segment. They can offer speed, safety, simplicity, and economy to everyone without the need for multiple systems.

Oct 05

Room To Move

If you’ve ever visited a water park, you’ve probably seen a “Lazy River” ride like Castaway Creek at Disney World’s Typhoon Lagoon or Rambling Bayou at Adventure Island in Tampa, Florida. They are shallow channels of water with a strong current. You can sit in an inner tube and just ride the current, or you can swim with the current, and get a boost that makes you feel like an Olympic swimmer. Some parks are completely encircled by a Lazy River that serves as a kind of transit system. The river is the guideway, and the stations are steps or ramps that lead into the water. In a Lazy River, traffic jams can actually be fun!

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Dec 04

How Big Can A City Be Before Traffic Becomes A Problem?

Sometimes it seems like the growth of a city is accompanied by even more growth in traffic congestion. At least that’s the impression I got living in Los Angeles during the years when most of its freeways were built. But was my subjective impression really true? The traffic patterns of real cities are so complicated that it can be difficult to discern the basic underlying principals. There are countless factors, not all of which are knowable, that influence the behavior of a transit system. So we have chosen to analyze a simple idealized traffic network to see how it works. If you’re curious, you can find the technical note How Transportation Network Size Effects Congestion on our Publications page.

Oct 01

The Tubenet Transit System

Tubenet Transit CityIn a recent presentation at the Podcar City 8 conference in Arlandal, Sweden, a new Chinese company called Tubenet Transit described their new PRT system, and how it could be used to accelerate eco-restoration and urban reforestation.  As the name suggests, the pods run inside of a tube with guide rails above the pod, and a support surface below.  The top of the tube is covered in solar panels.  The bubble-shaped pod is only two meters long, with an empty weigh of 150 kg (330 pounds), and a carrying capacity of 250 kg (550 pounds), seating two adults and one child.  (Remember China’s “One Child Policy”?)  They described three tiers of guideways, supporting speeds of 40, 60, and 80 km/h (25, 37, and 50 mph).

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Nov 26

SJSU Spartan Superway Design Workshop

SJSU Spartan SuperwayOn November 23rd, I had the opportunity to attend a student design workshop for a new Automated Transit Network (ATN) system.  This interdisciplinary project of San José State University involves the departments of structural, mechanical and electrical engineering, computer science, industrial design, urban planning, business, and public administration.  The students and their faculty advisors have actively sought out the advise and counsel of ATN experts from around the world.  The Mineta Transportation Institute (also at SJSU) and the City of San José Department of Transportation are also in communication with the student team.

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