When I was in my third year at the University of Waterloo, I lived in the west end of town, off Keats Way. My commute by bicycle commute was generally quite enjoyable by North American standards, it took place almost entirely on quiet streets or in dedicated bicycle lanes. And it was very fast too! The 2.1 km trip took about 8 minutes, and if I was lucky with the one traffic signal, I could make the entire trip home without stopping once.
Here was my route, categorized by my comfort level (green is relaxed, red is stressed):
The worst part of my journey was making the right turn off University Avenue onto Keats Way. Right-turning cyclists share the right turn lane with motor traffic turning right, which often results in motorists speeding past and cutting in front of cyclists to save a few seconds. Even when drivers would remain a safe and respectful distance behind, I felt pressured to ride quickly to avoid delaying them, adding stress to my otherwise relaxed commute.
Cyclists travelling straight along University are also exposed to this same conflict, as the bicycle lane runs between the through lanes and the right turn lane. While it’s not statistically clear that this is actually a dangerous situation, it certainly feels very unsafe – making cycling along this route an unattractive prospect for the majority of people.
Keeping the bike lanes always on the right of the traffic lane rather than merging them together would completely eliminate interactions with motor traffic for right-turning cyclists. This would move the conflict point onto the actual intersection for through cyclists, where it can be addressed separately.
I think that the best solution here would be fully-protected signal phases. This means that turning cars and bicycles would each have their own dedicated signal, which only allows one to proceed while the other is stopped at a red signal.
The usual way of managing this conflict – where turning cars yield to bikes and pedestrians – would be considerably more dangerous. In order to allow large vehicles such as GRT’s Route 29 bus to make the turn, the corner radius needs to be very large. This would then translate to high turning speeds for cars, which increases the risk that a car fail to yield to a cyclist or pedestrian crossing Keats Way.
Here’s what the intersection could look like with protected bike paths and traffic signals:
Protected signal phases can actually be implemented efficiently here because the bulk of the movements are compatible with each other. For the most part, people are travelling straight along University or turning off Keats Way to/from the east.
Hardly anyone makes a left turn from University to Keats Way or a right turn off Keats Way onto University since this would be basically sending them back the way they came. This last signal phase would therefore hardly ever occur:
Elaborating on the idea
(For the more technically-interested)
Since this intersection has bothered me for years, I’ve had plenty of time to come up with a potential signal operation that provides a decent balance between safety and delay for all modes. I’ve preferred a variety of different layouts over the years, but this is the one that I favour at the moment.
The co-ordinated (default) phase for the signal is east-west along University Avenue.
With protected signals, no right turns would be permitted while the bicycle and pedestrian signals are green and walk. Since that would be really annoying when no pedestrians or cyclists are around, pedestrian and bicycle phases could be provided on-demand, with the right turn signal resting in green the rest of the time.
To minimize delay for cyclists, bicycles would be detected about 40 metres* in advance of the intersection, giving the signals enough time to terminate the right turn phase and provide a green bicycle indication before the cyclist arrives.
*Assuming 3 seconds amber and 2 seconds all-red for the right turn signal.
To further increase the efficiency of the intersection, a shortcut path could take right-turning bicycles off University Avenue before the detector, keeping them from unnecessarily calling the bicycle phase.
The next phase group is the protected left turn off Keats Way, which is paired with the right turns off University.
I think the low-volume right turn movement off Keats Way could be effectively managed with a Leading Bicycle/Pedestrian Interval rather than fully-protected signal phases. An LPI/LBI is where the bicycle signal turns green a few seconds before the main traffic signal, giving cyclists a head start to reduce the chance that a turning vehicle fails to yield. To further manage the conflict the road geometry is such that bicycles and turning cars cross a right angle, keeping both groups out of each others’ blind spots. The corner radius is also kept to a minimum to keep turning speeds low.
Not using fully-protected phasing for this movement reduces delay for everyone because it eliminates the need for these vehicles to call the next phase.
The final phase group is for the unlikely event that someone wishes to turn left off University Avenue onto Keats Way. Although this movement is extremely low-volume, it needs to be fully protected because I included a 2-way bicycle path on the north side of University Avenue between Keats Way and Westmount. This path eliminates the need for cyclists to make two left turns to get from Keats Way to the University of Waterloo. At the moment many people accomplish this by riding the along the north sidewalk, placing both themselves and pedestrians in danger.
The conflict between left turning traffic and bicycles travelling the same direction to their left is one of the most dangerous situation that can exist in bicycle infrastructure. Fully-protected phases for left turns across 2-way bicycle paths are therefore an absolute necessity.
If there is a bicycle waiting to turn left onto Keats Way, that bicycle signal would come up concurrently with the corresponding left turn signal off University, otherwise the through vehicle signal would come up.
I have not included a pedestrian crossing on the north (grid east) side of the street since it would massively increase the chance that this phase gets called, and it would nearly double the amount of time it takes. The amount of inconvenience caused to pedestrians by eliminating this crosswalk is minimal because pedestrians heading southwest can just as easily use the west crossing here, and pedestrians heading southeast can just as easily use the crossing at Westmount. And in return pedestrians benefit from increased safety while crossing the street on any side.
Looking southbound (grid west) on University Avenue: The rightmost pair of motor traffic signals are Right Turn Signals.
Looking eastbound on Keats Way. The rightmost pair of signals are ordinary (green ball) signals – turning cars must yield to cyclists and pedestrians. Alternatively, 4-section heads could be used (as in my phasing diagrams above).
Looking northbound (grid east) on University Ave, the left pair of signals are Left Turn Signals.