About Surface Teatment Programs (Measure A and State and Federal Funded Contracts)
Surface treatment contracts are major construction projects funded by Measure A and State and Federal Grant funds. The contracts include scrub seals, micro-surfacing, fog seals, asphalt concrete overlays, curb, gutter and sidewalk repairs, street tree replacement and maintenance, and major pavement rehabilitation and reconstruction. The street locations for this work are listed each year in the Division’s Road Maintenance Annual Plan (RdMAP). The projects are advertised and awarded to the lowest responsible bidding contractor.
The concept of preventive maintenance promotes the principal that pavement life can be significantly extended through periodic seal coating, resurfacing and patching.
The following roadway surface treatments are designed to prolong the life of roadway pavement using the preventive maintenance concepts described in Introduction to the RdMAP.
What is a Scrub Seal?
A Scrub Seal is a four-step process in which a unique polymer-modified, asphalt-recycling agent is applied to a pavement surface at a rate of .15 -.45 gallons per square yard, depending on the pavement condition and cover aggregate. A specially designed drag broom is then pulled through the emulsion to fill cracks and voids left open by the initial application. An even coat of chips or other readily available aggregate is applied over the emulsion at a rate of 10-25 pounds per square yard, and finally, the seal is rolled over with pneumatic tire compactors. We do each of these steps in close succession to minimize lane closure duration. A Scrub Seal extends pavement life by seven to twelve years, and costs one-third the amount of a traditional overlay.
What is a Micro Surfacing?
Micro Surfacing is a polymer-modified, cold-application paving system, developed in Europe in the 1970s. It is a mixture of oil and high quality aggregates, designed to set quickly and provide a long-lasting surface on good, sound pavements.
What is an Asphalt Concrete Overlay?
An asphalt concrete overlay is asphalt concrete placed on the roadway approximately 0.15' thick. This treatment is designed as a structural improvement to the roadway. Asphalt concrete overlays with proper preventive maintenance strategies will provide approximately 20 years to the serviceable life of the roadway.
When does the County perform Street Tree Maintenance?
Street tree maintenance includes tree trimming, concrete repairs, tree complaint investigation, stump grinding, tree removal, tree planting and watering. There are approximately 13,000 street trees countywide, requiring maintenance. Tree trimming occurs in the Urban Forest, and on rural roadsides. In the urban setting, trees are pruned in an attempt to provide a balanced and standard look to the designated street trees in the parkway strip. Trees are also trimmed when necessary prior to resurfacing operations and other maintenance activities. Trimming is also done in rural and urban areas to insure sight distance, and to daylight signs. More on the County Street Tree Policy...
Does the County clean Culverts?
Yes. Culvert maintenance includes cleaning and reshaping drainage ditches, maintaining paved ditches and berms, culvert and inlet cleaning, headwall maintenance and construction and culvert installation and replacement. The annual maintenance of these facilities is essential to roadway safety. Also, the quicker water is removed from the pavement the more advantageous it is for the life of the pavement. Water permeates asphalt/cement and penetrates into the subgrade-removing fines, creating voids, and causing stress. When loads are placed over time, cracking develops causing the eventual disintegration of the pavement. The quicker water is drained from the roadway the less this aging process takes place.
What is Traffic Control Maintenance/Safety Assessment?
Traffic control maintenance includes striping, stenciling, curb painting, sign installation and maintenance, traffic signal maintenance and repairs, safety markers. It also includes bridge and guardrail repair and replacement as well as barricade, cattle guard and other minor structural maintenance. During winter storms or other naturally occurring events, the investigation and assessment of road conditions by county staff is necessary. Typically, phone calls from the public or public safety officers alert staff to potential hazards requiring assessment and action.
What is the Service Request Program?
During the daily the Road Maintenance Section, the staff receives requests from the general public to investigate public roadway concerns. The road condition is investigated and in most instances the necessary work is performed. In instances where damages are beyond the scope of routine maintenance, a project is initiated and the attempt to secure funds is made. Generally these projects are considered for funding during the next RdMAP preparation cycle.
What is a Project Initiation Request (PIR)?
The road maintenance staff receives over 800 requests for road repair per year. All requests are promptly investigated. In most cases, maintenance crews are able to repair the problem as part of the general maintenance plan. When, however, the scope of work is beyond that of routine maintenance and other departments, sections or agencies must be utilized, the Project Request Form must be completed to initiate the work.
The Project Request Form is entered into the department database that tracks all multi-departmental/sectional requests. After the staff investigates the request, the project is entered on the backlog database for one fiscal year. If a request is not funded during the year it was submitted, it must be reapplied for in the next year for funding consideration. This process is used due to the significant volume of requests received annually. Since available funding is capable of correcting a small number of these requests, the Transportation Division asks that requests be resubmitted in order to establish a list that reflects the most immediate concerns.
The public can initiate requests via phone contact with department staff, written request, e-mail, or by attending one of our annual public workshops. Get the PIR here... fill out and mail to: Project Initiation Request c/o Gena Valentine-Felix, 123 E. Anapamu Street, Santa Barbara, CA 93101
About Speed Limits: How are Speed Limits determined?
Speed limits are based upon the fact that most people can be relied upon to drive at a reasonable and prudent speed under most circumstances. Generally speaking, speed limits that reflect the behavior of the majority of motorists are found to be successful. Speed limits set arbitrarily low create violators of the majority of drivers and fail to command the respect of the public.
The speed at which most motorists drive is influenced by the roadway, roadside and the current traffic conditions. Many people believe that installing lower speed limits will always cause motorists to slow down and will consequently reduce accidents. Past studies indicate that this is not the case. Posting unreasonably low speed limits will make some drivers ignore the signs while some others try to obey them. This may create safety concerns because of the difference between faster and slower motorists.
Speed limits in California are governed by the California Vehicle Code (CVC), Sections 22348 through 22413; also, pertinent sections are found in Sections 627 and 40802.
California's Basic Speed Law (CVC § 22350) provides that:
No person shall drive a vehicle upon a highway at a speed greater than is reasonable or prudent having due regard for weather, visibility, the traffic on, and the surface and width of, the highway, and in no event at a speed that endangers the safety of persons and property.
This law recognizes that driving conditions can vary, and no single speed limit will adequately serve all conditions. The basic speed law is founded on the belief that most motorists are able to modify their driving behavior properly based on the conditions around them.
Maximum Speed Limits:
According to the California Vehicle Code section §22349, no person may drive a vehicle upon a highway at a speed greater than 65 miles per hour, and no person may drive a vehicle upon a two-lane, undivided highway at a speed greater than 55 miles per hour.
These are absolute limits, which may not be legally exceeded unless they have been posted for a higher speed as determined by the State Department of Transportation or appropriate local agency upon the basis of an engineering and traffic survey.
Prima Facie Speed Limits:
All other speed limits are prima facie limits, which are considered reasonable and prudent under normal conditions. Prima facie speed limits are either established by law or by an engineering and traffic survey.
Speed limits established by law are based on a particular condition such as traversing an uncontrolled intersection or driving through a residence district. Conditions where prima facie speed limits are established by law should be readily apparent and therefore do not require posting.
Whenever a local authority determines that the maximum speed limit or a law established prima facie speed limit is more or less than reasonable or safe, the local authority may determine a prima facie speed limit upon the basis of an engineering and traffic survey. Speed limits established upon the basis of an engineering and traffic survey result in increased safety and fewer collisions because it facilitates traffic to flow at a uniform speed and promotes the orderly movement of vehicular traffic on any given roadway or on any given section thereof.
Prima Facie Speed Limits Established by Law:
According to the California Vehicle Code §22352, the prima facie limits established by law are as follows:
Fifteen miles per hour:
(A) When traversing a railway grade crossing if during the last 100 feet of the approach to the crossing the driver does not have a clear and unobstructed view of the crossing and of any traffic on the railway for a distance of 400 feet in both directions along the railway.
(B) When traversing any intersection of highways if during the last 100 feet of the driver's approach to the intersection the driver does not have a clear and unobstructed view of the intersection and of any traffic upon all of the highways entering the intersection for a distance of 100 feet along all those highways, except at an intersection protected by stop signs or yield right-of-way signs or controlled by official traffic control signals.
(C) On any alley.
Twenty-five miles per hour:
(A) On any highway other than a state highway, in any business or residence district unless a different speed is determined by the local authorities.
(B) When approaching or passing a school building or the grounds thereof, contiguous to a highway and posted with a standard "SCHOOL" warning sign, while children are going to or leaving the school either during school hours or during the noon recess period. The prima facie limit shall also apply when passing any school grounds that are not separated from the highway by a fence, gate or other physical barrier while the grounds are in use by children and the highway is posted with a standard "SCHOOL" warning sign.
(C) When passing a senior center or other facility primarily used by senior citizens, contiguous to a street other than a state highway and posted with a standard "SENIOR" warning sign.
Prima Facie Speed Limits Established by an Engineering and Traffic Survey:
State law allows local authorities to raise or lower established speed limits on the basis of a traffic and engineering survey. According to the California Vehicle Code §627, an engineering and traffic survey is a survey of highway and traffic conditions in accordance with methods determined by the (California) Department of Transportation.
An engineering and traffic survey shall include consideration of the following:
1. Prevailing speeds as determined by traffic engineering measurements.
2. Accident records.
3. Highway, traffic, and roadside conditions not readily apparent to the driver.
An engineering and traffic survey may consider all of the following:
1. Residential density.
2. Pedestrian and bicyclist safety.
Prevailing speeds are determined by a speed zone survey. The intent of a speed zone survey is to determine the actual speed of unimpeded traffic. Speed limits are normally established at the nearest five-mile-per-hour increment of the 85th percentile speed (the speed at which 85 percent of the motorists are traveling @ or below on the surveyed roadway). Speed limits higher than the 85th percentile are not generally considered reasonable and prudent. Speed limits below the 85th percentile do not ordinarily facilitate the orderly movement of traffic and require constant enforcement to maintain compliance. Studies show that establishing a speed limit at less than the 85th percentile speed generally results in an increase in collisions rates.
Where conditions not readily apparent to the driver exist as indicated in collision records, speed limits may be set five miles per hour below the nearest five-mile-per-hour increment of the 85th percentile speed. If the speed limit to be posted has had the five mile per hour reduction applied, then the conditions and justifications for the lower speed limit shall be documented on the engineering and traffic survey by a registered Civil or Traffic Engineer.
Speed Traps (CVC § 40802)
Prima facie speeds may not be enforced by radar or any other electronic device that measures the speed of moving objects unless the speed limit has been justified by an engineering and traffic survey within the last seven years. The time provision for an engineering and traffic survey may be extended to ten years if no significant changes in roadway or traffic conditions have occurred, including changes in adjoining property or land use, roadway width, or traffic volume as determined by a registered engineer. A speed trap shall not apply to local streets, roads or school zones. A local street or road is defined by the latest functional usage and federal-aid system maps submitted to the Federal Highway Administration.
For further discussion on speed limits, please read the following article: Who decides speed limits? Here's the surprising answer by Tony Bizjak, The Sacramento Bee
About Traffic Signals: Will traffic signals help reduce the number of accidents at intersections?
Properly placed and warranted signals can improve the overall flow of traffic, but they do not always prevent accidents. Very often, accidents of certain types increase after traffic signals are installed.
Signals can be very effective in reducing right-angle collisions, but they could lead to increases in "rear-end" type collisions and other kinds of accidents. Some pedestrian-related accidents may occur because pedestrians get a false sense of security when crossing signal-controlled streets.
According to conclusions drawn from two studies recently conducted here in California, signals may have an adverse effect when installed at sites where there were only minor problems prior to the installation of the signals. The first study included more than 1,000 new signals and the second included 24 major California cities.
A related third study, called the Schoene study, warns of a possible increase in accidents whenever signals are installed at intersections where there were fewer than 10 right-angle accidents per year prior to signalization.
Signals installed at collector and local street intersections may be necessary for improving access to major streets, but they can also result in more neighborhood cut-through traffic.
When should Traffic Signals be installed?
The following are some points Traffic engineers take into consideration when deciding whether a traffic signal should be installed.
· Is the volume of vehicles entering an intersection creating dangerous confusion or congestion?
· Is traffic on the busy street so heavy that drivers on the side street will try to cross in an unsafe manner?
· Is there often a considerable crowd of pedestrians waiting to cross a wide, busy, and high-speed street?
· Do school children clearly require a traffic signal to cross the street with safety?
· Would the signal affect traffic flow adversely because of incompatibility with another near-by signal?
These are just a few of the points traffic engineers take into consideration for determining when traffic signals should be installed.
Before making such determination, traffic engineers first assess whether the conditions at potential traffic-signal locations meet the requirements established in nationwide standards.
When the established appropriate standards and conditions for installing a traffic signal are met, the signal will normally operate effectively. When those standards and conditions are not met, the signal may only cause more problems.
About Stop Signs: Will more stop signs help reduce speeding on our streets?
Under the right conditions, STOP signs can be very effective in improving traffic safety. The right conditions for installing STOP signs are determined through existing National Standards. Some factors considered in such standards are:
1. Traffic speed
2. Number of vehicles
3. Sight distance
4. Frequency of traffic gaps that allow safe vehicle entry and pedestrian crossing.
Most drivers are prudent and reasonable. Unnecessary and unreasonable STOP signs only generate their contempt for traffic signs and will make them likely to violate those devices. Such violations may often have tragic results. In other words, STOP signs may sometimes cause more problems than they solve.
STOP signs should normally stop traffic on the street with lower traffic volume. When both streets have similarly high volumes of traffic, four-way STOP signs should be installed. A traffic volume of 500 cars per hour during a substantial portion of the day is a determining factor for installing four-way STOP signs.
Installing, four-way STOP signs is usually not recommended when traffic at intersections is unbalanced. When the volume of traffic flowing on street A is considerably larger than the one flowing on street B, motorists driving on street A will tend to consider stopping at that intersection as illogical and useless and will only do "stop-and-go" or "roll-on" types of stop. This could increase the possibilities of accidents.
Installing a STOP sign in only one of two intersecting streets, however, tends to encourage drivers on the other street to increase speed since they have the "right of way" and they know others have to yield to them.
People often request STOP signs for street intersections in their neighborhoods hoping to force speeding motorists to slow down. However, as some nationwide studies show, STOP signs can generate a high number of intentional violations when installed as a speed control or nuisance device.
According to some studies, vehicle speed is actually reduced in the immediate area where nuisance STOP signs are installed, but vehicle speed is also increased between stop intersections. This results from motorists making up for the "lost" time they spent at the stop sign.
Nuisance STOP signs also increase fuel consumption, air pollution, and traffic noise.
In general, low-traffic-volume neighborhood street intersections regulated under the State of California Right of Way law tend to operate better without STOP signs. This law requires all motorists approaching intersections from all converging streets to slow down to reasonable speeds.
The State of California "Right of Way" law as stated in Vehicle Code § 21800 (b) (1) requires that:
When two vehicles enter an intersection from different highways (streets) at the same time, the driver of the vehicle on the left shall yield the right-of-way to the vehicle on his or her immediate right, except that the driver of any vehicle on a terminating ("T") highway (street) shall yield the right-of-way to any vehicle on the intersecting continuing highway (street).
It may be very difficult to remove STOP signs once they are installed. Therefore, we must be sure from the outset that their installation will be beneficial to all modes of transportation.
About Warning Signs: Will "Children at play" signs improve the safety of our children?
Yellow traffic and pedestrian warning signs are basically used to provide a safe and orderly flow of vehicles and people in our streets. They also provide motorists, pedestrians and cyclists with ample warning of impending conditions.
However, unnecessary signs can be distracting and confusing to motorists, making them disrespectful of the safety measures and the people they are designed to protect.
Unnecessary signs produce a dangerous false sense of security in pedestrians. A clear example of this is the "Children at Play" sign.
Facts indicate that this sign does not protect neighborhood youngsters as it is intended to. There is no evidence showing that these signs have helped reduce vehicle speed and pedestrian accidents in the residential areas where they have been installed.
There is no need to install signs in residential areas to "warn" motorists about already-existing normal conditions. When such signs are installed, they only give children and pedestrians a false sense of security and thus fail to improve safety.
Children should not be encouraged to play in the street. In fact, Federal standards reject these signs because they openly suggest that playing in the streets is acceptable.
Children live on nearly every residential block. Placing those signs in one street would require placing them in every street. Otherwise, streets with no signs might imply that no children live in that area and that motorists have the right to speed there.
There are signs designed specifically for schools and crosswalks that serve a clear and practical purpose. Because of the concerns they raise, "Children at play" signs are not recognized traffic control devices and are not used in most areas within California.
Warning signs are effective tools only when used to alert motorists of uncommon hazards.
Last updated: June 27, 2011