The size of the proposed new town and transportation system is ultimately limited by the maximum acceptable travel time on the LLM network from the outer ends of the LLM radial streets to the city center. This constrains the town to a maximum diameter of about 6.5 km (4 miles). A town of this size would accommodate 50,000-100,000 people.
A maximum diameter of 6.5 km maximum ensures that travel times on the LLM network are reasonable. If, for safety reasons, LLMs are built so that they cannot exceed 40 km/h, then an average trip of 1.5-2.5 km into the center would take about 5 minutes, while a trip across town would average about 10 minutes. For comparison, these travel times are similar to those for present suburban road networks. It is expected that many people would be willing to use bicycles, at least occasionally for trips of 3 km or less, on a convenient, safe cycling network. Thus, the radial LLM streets (and adjoining bicycle and pedestrian paths) should generally not exceed 2.5 km in length. If the town center has a radius of 0.8 km, the town itself would be no larger than 6.5 km in diameter.
Figure 24.2 illustrates a complete radial section of the LLM and FHV networks from the outer FHV beltway to the service core in the center of town along one LLM/FHV neighborhood branch. With a maximum 6.5-km diameter, the whole community (which certainly does not have to be precisely circular, but which is presented as such for convenience) has a maximum area of about 33 km2. At relatively high suburban commercial and residential densities, this accommodates as many as 100,000 people—probably the upper limit for a single town/transport network. At cozier dimensions and lower densities, the plan would accommodate around 50,000 people, which may be preferable. At this size, the town would have its own postal code and main post office, its own high school, civic and institutional center, recreational and entertainment programs, library, and community park as well as a viable commercial/retail core. Other facilities of regional importance (e.g., a college campus, theme park, government buildings) could also be accommadated.
Therefore, this plan allows growth of a transportation network and community from just one short radial arm and a rudimentary town center (i.e., a few thousand people) up to a small city of 100,000 people. A rudimentary town can also grow into a larger town by adding or extending neighborhood branches or by increasing the density along existing branches and in the town center.
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