Roundabouts

If there’s anything I liked in last week’s news, it’s the one about roundabouts, in a theoretical and academic way. There were two proposed ideas, the other one on U-turn slots, which I don’t favor. But roundabouts? – my son Samuel would be thrilled! Every time we drive around the city, he will always complain why there is only one roundabout here --Osmeña Boulevard. He couldn’t forget his two-week vacation two years ago, in Sydney, Australia, where roundabouts are almost everywhere.

Roundabouts are a type of traffic intersection design which has a generally circular shape, with yield controls on entry, and geometric features that create a low-speed environment. Roundabouts have been proven to demonstrate improved safety, better operational performance, and other benefits compared the traditional signalized intersections, even with the slower speeds. “Rotundas,” as they are called in the Philippines (and other “hispanized” countries), are actually not new – these proliferate in England, France, and other European countries and their erstwhile territories – Australia, New Zealand, etc.

The technical advantage of roundabouts is its slower but continuous speeds compared the faster speeds but with the stop-and-go control, which introduces the time loss due to acceleration, deceleration, and idling time. The slower speed is a big plus, too, safety-wise, introduces traffic-calming effects, and enables one to enjoy the scenery – the central island and splitter islands of

fer the opportunity to provide landscaping, monuments, and art, much better than the drab, yellow asphalt boxes we have.

The only major disadvantage it has over the regular intersection is that it requires quite a bigger area of land. If we do the transport economics, I believe this can be compensated by the transportation benefits, depending on the price of land. For new intersections planned, this might not be a problem, but for existing crossroads, the road-right-of-way costs would be a real challenge.

The most congested areas in Cebu are along those intersections where there are already huge, tall edifices in all corners. If we redesign those for roundabouts, we would be tearing down a lot of buildings at huge costs. Roundabouts also offer challenges to pedestrians and bicyclists since they would need to traverse longer routes, which is counterproductive to inclusive mobility, but these can be compensated by providing the proper infrastructure. The other disadvantage is most Filipinos don’t know the unique traffic rules in roundabouts. Just observe Fuente Osmeña today and see all those violations!

As to U-turn slots, we have to make studies first, or read existing ones. A study by the National Institute of Physics in UP Diliman showed that the Metro Manila U-turn slots were good only for lower Vehicle-Capacity Ratios (VCRs) but become adverse for higher VCRs. Major intersections in Cebu already have VCRs of 1.0 or higher, U-turn slots would only make them worse. Whether U-turn slots or roundabouts, studies should be done first, and must be location-specific. Not all intersections are the same. My cursory take is, let’s do roundabouts, but for new or less-developed intersections. As for U-turn slots, it’s better to just invest in smart signalized traffic management instead.