I just read two letters in your Nov. 9 edition regarding traffic circles for St. Davids, (“St. Davids needs a roundabout – at York and Concession 6” and “Hold a referendum on St. Davids roundabout plan.“)
I also found that Alperen Albayrak’s editorial cartoon on the subject hit upon the real problem with these traffic management devices. Too much management and too little space.
For the last 75 years, traffic conflicts at intersecting highways have been handled by the construction of what are generally referred to as cloverleafs.
No 90-degree conflicts, no stop signs and no traffic lights solved things very well.
Their one drawback is that as time passed, traffic and municipalities both grew fairly rapidly and eventually, as shown in your cartoon, conflicts developed when a needed cloverleaf could not be constructed at the scale traffic engineering recommended due to conflicts with built up areas at the same locations.
Some cloverleafs were modified to fit into the available space resulting in some T-intersections where on-ramps met the main roads and in sharper turns on the on-ramps.
This made them less effective, even when some of the additional exproriation costs were accepted.
The move to replace costly and underperforming cloverleafs resulted in the move to traffic circles and the newer double-diamond interchanges.
These, however, also only worked efficiently when thay were constructed using the proper scale and area of land.
The traffic circles found throughout Niagara generally have been built using insufficient land area and too small a diameter of the main component.
It would be in everybody’s long-term interest to build these junctions only if they can be constructed large enough to work properly and safely.