Tag Archives: Density


Below are additional reports and analysis on Light Rail projects in the United States

Sustainable Growth?

“Charlotte … perform(s) particularly bad. These systems do not have enough riders to produce the economies of scale that make transit provision by rail significantly less expensive than bus.” — UC Berkeley Urban Densities and Transit: A Multi-dimensional Perspective

While public transit is required to help accommodate the area’s population growth, the central question is what technology do we require to solve what problem? And when do you use one versus the other? So where rail transit might be economically sound by re-purposing along existing rail corridors surrounded by high-density populations, does it make sense to use rail transit all of the time? Is rail the only tool in the transit kit?

What really matters to transit-oriented development [TOD] outcomes?  According to the report, the #1 predictor is strong government support for redevelopment, while the #2 predictor is real estate market conditions.  The #3 predictor is the usefulness of the transit services — frequency, speed, and reliability as ensured by an exclusive right of way. Using rail vs bus technologies does not appear to matter much at all. — yes, great bus service can stimulate development!

There seems to be a continued LRT bias where advocates claim that LRT is the only way to support population growth using TOD (Transit Orient Developments) and that TOD has an inherent affinity for LRT over BRT. However, studies from the US GAO (BUS RAPID TRANSIT, Projects Improve Transit Service and Can Contribute to Economic Development) and a recent study of 21 North American transit corridors across 13 cities by the Institute for Transportation and Development Policy suggests otherwise. The study concluded that strong government support for redevelopment and real estate market conditions were the primary drivers that drove successful TOD. The use of transit technologies (rail vs bus) did not matter at all.

Outside of the US, in cities like Curitiba, Brazil, and Guangzhou, China, there is copious evidence that BRT systems have successfully stimulated development. Curitiba’s early silver-standard BRT corridors, completed in the 1970s, were developed together with a master plan that concentrated development along them. The population growth along the corridor rate was 98% between 1980 and 1985, compared to an average citywide population growth rate of only 9.5%.

Many cities, therefore, consider investing in mass transit to stimulate the hoped-for development. Indeed, a good mass transit investment can be such a catalyst. Yet city planners and politicians, who do not always work closely with transportation professionals, commonly begin to view mass transit in and of itself as a silver-bullet solution for stimulating development. — ITDP study, More Development For Your Transit Dollar

The DOLRT study area projects 32% population growth. It is the lowest projection of the counties and regions in the study, suggesting that there are other population areas that are growing substantially FASTER than the DOLRT corridor.

Based on the Alternative Analysis, the corridor study area is projected by 2035 to have a population density of 4052 ppsm or people per square mile (231K / 57). Using 1/2 mile walk-up radius around each of the 17 proposed stations, approximately 68,000 people will be within walking distance of a station. The national average for public transportation utilization is 5% (Durham 3%). This suggests walk access will be approximately 6800 daily boardings (68K * 5% * 2) rather than the projected 12,180 by GoTriangle in 2040.


“It is broadly accepted that fairly dense urban development is an essential feature for a successful public transit system. Our analysis suggests that light-rail systems need around 30 people per gross acre … (for) cost-effective investments in the US … urban densities are the most critical factor in determining whether investments in guideway transit systems are cost effective” — UC Berkeley Urban Densities and Transit: A Multi-dimensional Perspective

So how much population density do we need to make light rail cost-effective?


Let’s do the math, there are 640 acres in one square mile. So that means we would require a density of 19,200 people per square mile. So with our current 3071 ppsm (175K / 57) along the DOLRT study corridor, that is 16% of the recommended population density. Or stated differently, we would have to reach a population of over 1 million people by 2040 (or today’s entire Wake county population) just within the 57 square mile study corridor.


The great enemy of the truth is very often not the lie — deliberate, contrived and dishonest —
but the myth — persistent, persuasive, and unrealistic.

Too often we hold fast to the cliches of our forebears.
We subject all facts to a prefabricated set of interpretations.
We enjoy the comfort of opinion without the discomfort of thought.

John F Kennedy, Yale University, June 1962

There are many myths about light rail train projects that are often repeated by light rail advocates that makes it very difficult to have a fact based discussion. This light rail bias has been well documented in grand jury findings and policy studies, yet they continue to persist. Without a fact-based discussion, we will squander large amounts of tax dollars for an inflexible and obsolete light rail system that will not align with high growth areas and new emergent transportation technologies. Here is a partial list of some of these recurring myths.

Who can I talk to and have my voice heard?

Some voices carry more than others. Your elected representatives will listen to you. You have the vote! How can I maximize my voice? Phone calls are heard very loud and clear. Hand written letters are the next best thing. Followed by typed letters delivered by US postal. And lastly email. So while most of us use (myself included) email … your elected representatives prefer to hear from you (literally). So if you want to maximize your impact, please call!