Schedule for November 10,  8 AM - 5:30 PM 

The slurry seal contractor will be performing spot patches, cleanup work, and other punch list items as part of project close out. Spot patch repairs will occur in the vicinity of the posted barricades only. It does not apply to the entire street. The work will be done weather permitting.

Traffic will have limited access through these streets during the street resurfacing process. Traffic controls within the construction area will be in place. Normal construction hours are Monday through Friday from 8:00 a.m. to 5:30 p.m.  Two days prior to construction, “No Parking” and “Tow-away” signs will be posted with the effective time and date.  Roads will be reopened to full traffic and parking at the end of each working day, however, during the construction period, loose gravel and an uneven pavement surface will result from removing the surface asphalt.  For the entire project, we estimate it will take 1 week for crack sealing, 2 weeks to repair damaged pavement sections, 1 week to remove traffic striping, 1 week to apply surface seals, and 1 week to repaint traffic markings. To maintain competitive prices, the contractor, G. Bortolotto & Co., Inc. (650-595-2591) is allowed to schedule the work in a cost effective manner which may result in a time lag between repair, required curing times, and resurfacing.  

Sun, heat and vehicle loads can break down roads, but the biggest enemy of a road is water. When water gets underneath the pavement, the road becomes weaker and, as vehicles use the road, the weakened parts of the pavement start pumping up and down and a pothole is born. To protect our roads from water seepage, the Town routinely patches or seals cracks and damaged areas. This helps to prolong the life of the road to avoid costly resurfacing or reconstruction.

The town generally maintains its streets using surface seal methods and rehabilitates its streets using grind and overlay methods.  The Town uses surface seal methods by applying seal coats to the asphalt surface to prevent pavements from deteriorating over time due to water permeation beneath the asphalt layer. Known as ‘slurry seal’, this method preserves the streets with pavements that are mostly in good condition without structural failures. The combined treatment is at least 10 times more cost effective than traditional reconstruction methods and can extend pavement life an average of 5 to 10 years.

Slurry Seal is a mixture of emulsified asphalt (oil), water, fine crushed rock, and sand.  It is a surface applied treatment designed to extend the life of existing streets in two ways.  It helps to maintain the integrity of the roadway by filling surface cracks and voids.  By replenishing roadway surface oils, it also acts as a water repellent cap, shedding water into the gutters and preventing water damage to the subsurface of the street. Slurry Seal is only used for preventive maintenance and is designed to extend the life of a pavement.  

Application of Slurry Seal is a two-step process.  First, surface cracks are filled and surface patching is done.  There is no parking on the affected street on the day this takes place.  Notices will be posted beforehand.  Several days after the crack sealing and surface patching, the Slurry Seal is applied.  Streets will be closed to both parking and driving during the application although limited driving will be allowed in case of emergency by Police and Fire.  Normal driving and parking will be allowed after the contractor removes the ‘No Parking’ signs at the end of the working day.  Slurry Seal requires only a few hours to dry before traffic can drive over it, but it takes 24 to 48 hours to cure completely.  During the first few weeks after the slurry seal application, residents should avoid excessive steering of their vehicle while it is standing still, or starting or stopping quickly as this may cause tire tracks and scuff marks on the surface.

Comprehensive road rehabilitation encompasses overlay methods that apply structural enhancements to the asphalt layer and improve load-carrying capability. The Town usually applies 1.5 to 3 inches of asphalt concrete overlays to streets with pavements that are in fair condition with mild to moderate levels of base failure.  Before the application of asphalt overlays, roto-milling removes approximately 1 ½ to 2 inches of existing pavement in order for new asphalt pavement materials to fully adhere to the surface. Preparatory work such as asphalt patching, edge milling and utility adjustments will be completed prior to any overlay work. These overlay treatments are at least 3 times more cost effective than traditional reconstruction method and can extend the service life of a pavement 10 to 20 years.

The pavement condition of Portola Valley’s street network is evaluated every 2 to 5 years. The condition survey grades the streets using a rating standard called Pavement Condition Index (PCI) which ranges from 0 to 100 with 100 representing an excellent pavement.

The Public Works Department consider the PCI scores of streets, the timing of public projects for water and sewer infrastructure, and the limited funding when selecting streets for a project. 

If you have any questions about the street resurfacing project, please call Howard Young, Public Works Director at 650-851-1700  or email at hyoung@portolavalley.net. 

To report concerns or anything that needs to be fixed please report on PVConnect 

Street list for surface seal treatment (a slurry seal):

In the slurry seal process, there can be material cure times of up to 1 week between the asphalt repair process and the application of the slurry seal top coat.

Note: The contractor will be hand delivering printed notices to residents 2 days in advance indicating the exact date your street is scheduled for the surface seal treatment phase (slurry seal) which will affect street access until the surface has cured and dried enough to allow traffic (typically 4-5 hours). On the surface seal date, we ask that you to make parking and schedule arrangements to avoid the work area and to turn off irrigation that would cause water runoff onto the street.  Please do not water or drive on surfaces until dried, it will affect the final look of the product and track onto surfaces. The garbage company typically will pick up garbage earlier that day if your street is affected. 

Crack seal Schedule

Click here for to see contractors posted flyer: 72-Hour Slurry Seal Notice

Please note: schedule is subject to change based on field conditions, progress, weather, and unforeseen conditions.

*Schedule Update 9/21/21 at 5:00 pm: 

Portola Stonegate to 815 Portola Road – Continuing work Weds/Thurs

Westridge Drive – Continuing work Weds/Thurs

Longspur – Lower half of one lane Weds, upper half Thursday  

 
In the slurry seal process, there can be material cure times of up to 1 week between the asphalt repair process and the application of the slurry seal top coat.

Note: The contractor will be hand delivering printed notices to residents 2 days in advance indicating the exact date your street is scheduled for the surface seal treatment phase (slurry seal) which will affect street access until the surface has cured and dried enough to allow traffic (typically 4-5 hours). On the surface seal date, we ask that you to make parking and schedule arrangements to avoid the work area and to turn off irrigation that would cause water runoff onto the street.  Please do not water or drive on surfaces until dried, it will affect the final look of the product and track onto surfaces. The garbage company typically will pick up garbage earlier that day if your street is affected.