Sprawl in perspectiveJust an interesting factoid: at our current average density of about 3,500 people per square mile (city limits), Houston's greater metro population of around 5 million would fit in a circle with a radius of 22 miles. Forecasts indicate we may add another 3 million people over the next 20-25 years, for a total of 8 million(!). Wanna take a quick guess what the radius of that circle would be?
A mere 27 miles. Just 5 extra miles. That's a single, solitary mile every 4-5 years. Not as many or as fast as you thought, huh? It's the power of the r-squared in the area=pi*r^2 equation. Of course, cities don't actually grow in a nice, uniform density - there are plenty of gaps and areas where the population stretches farther out (usually along freeways), plus the natural densification of the core. But the math shows how cities can seem to have galloping growth early on, as each mile of additional radius just holds a small number of people, yet that radial growth must inevitably slow as the additional miles can accommodate ever more people.
One implication: the Grand Parkway is likely to be the last loop we ever need.