So how do you plan an automated roadway network for a specific city? The first step is to develop a conceptual overall master grid layout. This is a grid custom-fitted to a given metropolitan area. It represents the goals of a fully implemented system. The MASTER GRID layout determines for all time how effectively the distances of travel between points can be minimized in that city. Too many compromises may permanently increase the distances vehicles are forced to travel.

The MASTER GRID must work around such geographical constraints as rivers, bays, mountains, and lakes. Man-made constraints are a different matter. Wherever an automated roadway is built, the city will follow. The direction and shape of the city will be determined by the Master Grid. If there is a substantial man-made obstacle, construction of that section of the grid might just have to wait – perhaps 20 years or more — until the obstacle is obsolete and is removed.

Conventional roads and streets through crowded cities have grown increasingly less efficient as local governments have compromised good road design to accommodate special interests. For example, meandering streets through subdivisions and master planned communities are attractive. But roads whose purpose is to provide regional travel from one part of a city to another need to be THROUGH streets and follow a rational pattern of connectivity appropriate to the metropolitan area.

There was a time when government growth-planning administrators required developers to reserve a fifty-foot right-of-way on the developer’s side of every township section line when they developed a project (townships are 1 square mile land parcels). This meant a through road could be built at one-mile intervals both north to south and east to west. Anyone buying property along a parcel’s boundary (if it was a section line) could reasonably expect a road might be built there, so if they had a problem with that, they might want to buy elsewhere.

If a county decided to build a road they had a 100-ft. right-of-way already clear of obstacles. It could purchase the land and build the road. The point is, for the MASTER GRID to be effective it must recognize physical geographical restraints, but should not be constrained by man-made obstacles.

The layout of a master grid for a given metropolitan area may be a composite based upon design elements of THEORETICAL TEMPLATES. Our template examples are rectangular, circular, and a diamond pattern.

Illustration 8
Rectangluar grid
enlarge image see animation

Illustration 8 shows a rectangular grid. Each automated regional roadway is a single lane in a single direction. All THROUGH traffic on the grid travels 120 mph. Regional automated transport roads alternate north and south at one-mile intervals and east and west at one-mile intervals. The circular roadways are INTERCHANGES. Vehicles use the interchanges to get from one regional roadway onto another regional roadway. The interchanges are also used to EXIT and ACCESS the REGIONAL roadway grid. When a vehicle EXITS an INTERCHANGE it decelerates to 80 mph or 50 mph depending on the LEVEL of SERVICE ZONE it is exiting into. As a vehicle exits into local or neighborhood roads it will decelerate to 20 mph.

In this configuration every location within the grid is an average of only one half mile from the EQUIVALENT of a SIX LANE LIMITED ACCESS INTERSTATE HIGHWAY.

Illustration 9 shows a circular grid. This might be appropriate for a metropolitan area like Indianapolis, Indiana, St. Louis, Missouri, Boston, Massachussetts, or Washington, DC.

.Illustration 9
circular grid
enlarge image

Illustration 10 is a triangular or diamond grid. This is more theoretical than practical. It is the most efficient layout to reduce distances of travel between points. Parts of a rectangular grid may use a diamond pattern in specific areas where a diagonal is the shortest distance connecting two very high traffic areas.

At the INTERSTATE level, a DIAMOND pattern may be more beneficial in the NORTHEAST USA from about Washington, DC through Maine because in the northeast highways and main city roads tend to oriented at an angle parallel to the northeast neck of the country.

The RECTANGLE pattern may be better for most of the MIDWEST and SOUTHEAST because the land is predominantly flat and many cities such as Chicago, Denver, Detroit, Dallas, Houston, Kansas City, Memphis, Miami, Milwaukee, Minneapolis, and Palm Beach are already laid out in rectangular grids with major thoroughfares at one mile intervals. Except where rivers are involved, most streets in the cities run north to sound and east to west.

West of the Rockies, roads in cities like Las Vegas, Los Angeles, Phoenix and Salt Lake City also tend to be patterned in rectangular grids.

Hypothetical Grid for Orlando, Florida
This illustration is a hypothetical grid for key parts of Orlando, Florida and its environs. This illustration depicts a grid only, without interchanges. Colonial Drive is a major east-west route that would continue to Florida’s east and west coasts. Another major north and south route would follow Orange Avenue to bring a high volume of cargo vehicles into and out of the downtown area. A diamond diagonal is used to carry traffic both ways to Disney. This allows a shorter, more direct path for every employee coming from north of this diagonal. This grid connects Orlando International Airport, Disney, Universal, Downtown, I-Drive, the Convention Center, all suburbs, employers, schools, shopping areas, restaurants, hotels and recreational facilities. This drawing just suggests some of the possibilities. Remember, in planning transportation routes, in the SHORT run transportation must be matched to the city. In the LONG run the city will grow to match wherever there is transportation.

Illustration 10
triangluar diamond grid

see complete grid

hypothetical grid to show greatly improved
travel time for commuters, easy cargo access
in and out of dowtown area, and high speed
access to and through city from outlying areas

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