Friday, July 15, 2011

Work products: Roundabouts.

This week I’ve focused on intersection design. New Anam City, lacking a grid connection, will not have the “luxury” of signalized intersections. Meanwhile, I think Lagos was the only place where I actually saw a stop sign.

Seems like the perfect place to integrate roundabouts. I am a huge fan of roundabouts – they are more aesthetically pleasing and safer, an elegant and simple solution to a complex traffic problem. Of course, I knew nothing of actually designing a roundabout, so it was back to research.

Fortunately, there are some excellent resources on roundabout design. Sometimes difficult to integrate the finer points of geometric design, I was able to put together a few ideas by the end of the week. My proficiency with AutoCAD is finally up to par compared to when I finished my bridge design job.

I am drafting “templates” of varying roundabout sizes, depending on the availability of ROW, traffic demand, and frequency of large trucks/semis. Another idea, fed to me by my managers, was what they call “Savannah-style” roundabouts, so-named because they saw examples of it in Savannah, GA. This configuration plays into their urban design ideas about central plazas that tie nodes of the city together.

I demonstrated how the Savannah configuration still requires intersection controls and how roundabouts would fit in nicely.

All of this is conceptual. The templates would inform development once the city really takes off. In the first phase of this project, the scale will be much smaller. Even so, it appears that a prototype could be installed soon (i.e. within the next eight months). There’s an intersection near the site that ties a state road to New Anam City. Located next to the proposed hospital site, a roundabout is particularly suited for its traffic calming effect and increased safety for pedestrians.

The design is incomplete, but well on its way.

Not exactly glamorous, but I find it fascinating. I love roundabouts. I love doing design work for a project that I care about – even when it means plunking away at AutoCAD for hours on end. This is an encouraging discovery. After my internship at Otak, I questioned whether I actually wanted to be an engineer: the 40-hr work week, the number crunching, the CAD work. It can get rather dull. Turns out, I really do enjoy civil engineering when it's for a good cause and I can feel ownership of the work I produce.

Next week: energy!

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