Anyway, here are my answers. But I have to confess that I am not 100% sure about some of them.
1) The roundabout at the junction of Queensway and Commonwealth Avenue was known as Queenstown Circus of course.
Correction. Correction answer should be Queens Circus as pointed out by reader Ngiam Shih Tung. For details go to this website. (22 Oct 2007)
2) The roundabout at the junction of Queensway, Farrer Road and Holland Road was known as Holland Circus.
3) The roundabout at the junction Alexandra Road, Queensway and Jalan Bukit Merah was known as Alexandra Circus. Actually I am just guessing here. I recall that there were some roadside barber shops nearby. They must have been relocated to Queensway Shopping Centre.
Correction. Correction answer should be Rumah Bomba Circus as pointed out by reader Ngiam Shih Tung. (22 Oct 2007)
4) The roundabout at the junction of Lorong 1, 2 and 6 Toa Payoh was known as Toa Payoh Circus. This was also a very huge one in terms of area - almost as big as the one at Queenstown.
5) The roundabout at the junction of Bukit Timah, Clementi and Anak Bukit was known as Bukit Timah Circus.
6) The roundabout at the junction of Serangoon Road, Macpherson Road and Bendemeer Road was known as Woodsville Circus. The PIE flyover there now is known as Woodsville Flyover. In Hokkien we called this place Sar Ko Chio or Three Mile Stone. There used to be many open-air hawker stalls here. When I was staying in Lorong Chuan, we occasionally come here to ‘tar pau’ supper; especially when we had friends staying over. My old friend Simon Chu was one of them.
This is a recent photo of what was formerly the Woodsville makan place. Today, there is a Kopitiam food centre at Jackson Centre and lots of other coffee shops nearby.
After this, Serangoon Road becomes Upper Serangoon Road. The junction of Upper Serangoon Road with Braddell and Bartley Roads was call Si Ko Chio (4 Mile Stone). Further down there used to be a market at Lim Tua Tow Road and this place was Gor Ko Chio (5 Miles Stone). Now you tell me where is Lak Ko Chio (6 Mile Stone).
7) The roundabout at the junction of Anak Bukit and Upper Bukit Timah Rd was known as Ewart Circus. It was removed only quite recently with the completion of the underpass joining Upper Bt Timah to Clementi Road. And there was another roundabout nearby, just in front of the Fire Station, but I don’t know the name.
And I left the toughest question to the last.