A rotunda in the SRP? (Part 2 of 3)

Last week, we compared the rotunda proposed at the South Road Properties with Fuente Osmeña. Let’s start with speed. Without traffic congestion, say at dawn, what’s the regular and fastest speed you can go around Fuente Osmeña? The limiting factor of this is the actual possibility of overturning, but the real limiting factor is the driver’s fear of overturning. That’s at dawn. The limiting factor for the rest of the day would still be traffic congestion, and that’s bad starting at 4 p.m., and you’d probably be lucky if you can traverse around Fuente at 35 kph.

As you may have seen in the data we laid out last Monday, the biggest single difference between the proposed rotunda at SRP and Fuente Osmeña is the size of the inner diameter island. Fuente Osmeña is a 120-meter diameter park, while the center island of the proposed rotunda at the SRP is only 40 meters. Now try to imagine Fuente Osmeña with only one-third the diameter, with seven lanes going around it. The issue is not the number of lanes --it’s the speed of the vehicles around it. The tighter the curve, the slower a vehicle will be, even if your driver is a daredevil. I am very sure DPWH already has the figures on what speed a car may go around the rotunda with a central island of only 40 meters in diameter. Will it be 35 kph?

This is the technical issue. While it might be seen positively by “turning left” people, it is grossly disadvantageous for people using the CSCR as through-traffic, of which it was originally designed for, and which number is far greater. CSCR was designed for 80, even 100 kph, although its speed limit now was cut by DPWH to 60 (by national regulation), which was further lowered down to 40 kph by local announcement. But everybody who passes by there knows no one follows the 40 kph limit, traffic permitting and without ECQ. You’re on your way to work, or going home, on a road designed for 80 kph and you drive at 40 kph? You’ll be like a snail in a sea of speeding rabbits and would actually pose a danger to the others. And that’s how the CSCR was approved --for its economic viability, too. At 60++ kph.

Now you put a rotunda in the middle, with a turning speed of 35 kph, what do you think will happen? The entire CSCR will slow down to 35 kph! Or thereabouts. Its total throughput in passengers per hour per direction, assuming no change in vehicle modal split, will be cut in half, especially the Cebu City-Talisay direction which will have two additional conflicts. That means that both time savings and vehicle operating costs savings will decrease too. There would be increases in the left-turning traffic and that has to be considered, too. Ultimately, the economic internal rate of return will be the net one and must be positive to justify that the rotunda is much better than the existing scenario? Did DPWH explain this and did the City Council study these permutations? (To be continued)