The process for a speed hump on Glenside Drive began with a Transportation Action Request (TAR), which the City received on January 28, 2019. The TAR applicants had a vehicle drive into his home and through several of their rooms. Staff looked through old files pertaining to that area to look for patterns/trends. Staff found the results below:
The Glenside Dr./Michael Lane curve has been a hotspot for accidents/property damage over the last couple of years. Within the last three years, there have been three incidents that resulted in police reports and not all of the incidents at this location made it into a police report. Staff can recount repairing the damaged guardrail on Glenside Dr. at least once in the last five years and property owners recall having their mailboxes/garbage bins damaged multiple times over the years. The problems/concerns the residents echoed were unsafe left turn movements from Glenside Dr. onto Michael Lane, excessive speed around the curve, and failure to completely stop at the Glenside stop sign, a few hundred feet away from Michael Lane, at Los Palos.
Prior to receiving a TAR requesting a speed hump, staff began with implementing less intrusive solutions, such as (1) pruning the trees/bushes for better line of sight around the curve, (2) replacing old/worn out chevron signs for better visibility of the upcoming curve, and (3) extending the striping of the left-turn lane for vehicles turning left onto Michael Lane from Glenside Dr. However, none of these solutions made the unsafe conditions any better. Many vehicles were still observed traveling over 25 mph when the recommended speed is 20 mph when entering the curve and some drivers were unable to remain in the clearly delineated lane.
In consultation with Traffic Engineer, Chuck DeLeuw, staff decided to try a temporary speed hump to physically slow drivers down to an appropriate speed. All of the asphalt speed humps in the City have a recommended speed of 15 mph, therefore staff chose a rubberized speed hump that stated would slow drivers down to 15 mph. Staff brought the request to install a temporary speed hump on the east side of Glenside Drive between Augustine Lane and Michael Lane to the Transportation & Circulation Commission on July 15. It was mentioned the speed hump would be re-evaluated for effectiveness in approximately six months. If you’d like to listen to the recording of the meeting, you can do so here: https://lafayette.granicus.com/MediaPlayer.php?view_id=2&clip_id=4487. The Transportation & Circulation Commission recommended the purchase of materials to City Council utilizing a sinking fund to purchase the speed humps, which was approved at the July 22, 2019 City Council meeting.
Since the installation of the temporary speed hump on October 17, the City has received many comments regarding the speed hump. To date, the number of positive comments and negative comments are about the same (17-15). We’ve also had some neutral comments (5) from residents who understood the need for the speed hump, but would request the City to install a lower one. Additionally, staff and residents have noticed vehicles are now travelling at an appropriate speed throughout the curve and staying within the delineated lane. Also, residents who turn left onto Michael Lane now state they feel much safer when doing so. The temporary speed hump achieved the goal of increased safety instantly when the previous, less intrusive solutions could not.
Staff acknowledges the height and harsher than intended speed hump, as well as the increased safety. Given the amount of feedback the City has received, staff is planning to bring this matter to the Transportation & Circulation Commission on January 6, 2020. At the January 6th meeting, the Transportation & Circulation will provide direction to staff on how to proceed. There will be two options for the Transportation & Circulation Commission; remove the temporary speed hump without replacement or replacement with a permanent speed hump that is more in line with other asphalt speed humps in Lafayette. All of the permanent speed humps in the City have proven they can be safely traveled over at 15 mph. This would also provide a more consistent flow along the south side of Glenside Dr., allowing vehicles to enter/exit Augustine Lane easier and safer. The typical process for installing traffic calming solutions requires Transportation & Circulation Commission approval. The City Council would not see this item come before them unless the action from the Transportation & Circulation Commission is appealed.
If you have any questions or comments regarding this, you can contact Justin Horng, Transportation Planner, at firstname.lastname@example.org or 925-299-3229.