The URL can be used to link to this page

Home My WebLink AboutItem 6.1 SilvergatePrpsdStpSigns /' I..ÔÍi . .~ / ./ CITY OF DUBLIN AGENDA STATEMENT City Council Meeting Date: November 13, 1990 SUBJECT: Public Hearing: Silvergate Drive - Stop Signs Proposed at Betlen Drive and at Castilian Road OR Amarillo Road (Report by Public Works Director Lee Thompson) EXHIBITS ATTACHED: 1) (#,2) RECOMMENDATION: 1) \,I: 2 ) 3) 4) 5) Resolution Report from TJKM Open public hearing. Receive Staff presentation and public testimony. Question Staff and the public. Close public hearing and deliberate. Adopt resolution. FINA1~CIAL STATEMENT: The estimated cost of installing STOP signs and related pavement markings on Silvergate Drive at Betlen Drive and at either Castilian Road or Amarillo Road is $2,000. An additional cost of approximately $250 would be incurred at Amarillo Road for removing existing "School Xing" legends. Sufficient funds have been budgeted in the Street Maintenance Operating Budget to cover these costs. DESCRIPTION: At the City Council meeting of October 8, 1990, the City Council received a presentation regarding alternative means of slowing traffic on Silvergate Drive. The proposed solutions included stop signs at the Betlen Drive intersection and the Castilian Road intersection, modification of the Dublin Boulevard/Silvergate Drive intersection, roadway geometries similar to those on Amador Valley Boulevard, and a frontage road concept similar to that on Alcosta Boulevard in San Ramon. Because of the cost involved and the lack of guarantee that the roadway geometries or frontage road concepts would solve the speeding problem, the City Council directed Staff to set a public hearing to review the need for STOP signs at Betlen Drive and at either Castilian or Amarillo. TJN~'s previous study indicated that STOP signs on Silvergate Drive at Betlen Drive did not meet the warrants. TJK}l has conducted a study of the Amarillo and Castilian intersections and prepared a report which indicates that STOP signs are warranted at Amarillo Road on the basis of traffic volume but not at Castilian Road; therefore, Staff recommends choosing Amarillo over Castilian. TJKM's report is attached as Exhibit 2. The attached report expresses a concern that with the installation of STOP signs, the warrants for the existing adult crossing guard at Amarillo Road would no longer be met. The warrants for crossing guards at controlled intersections specify 500 vehicles per hour during the period of time that children are going to school but only 350 vehicles per hour at uncontrolled intersections. Staff does not recommend removing the crossing guard at this time. In response to a request made at the October 29th meeting, the Traffic Safety Committee is currently evaluating the traffic situation on Amarillo Road at Nielsen School and,will be presenting a report at the November 26th meeting which addresses crossing guards and other control devices. After the study is complete, Staff will make a recommendation as to whether the existing crossing guard should be transferred to a location on Amarillo Road. Staff recommends that the City Council conduct a public hearing, deliberate, and adopt the resolution for installation of STOP signs on Silvergate Drive at Betlen Drive and at Amarillo Road. ---------------------------------------------------------------------------- ITEM NO.ÁL COPIES TO: TJKM TRANSPORTA nON CONSUL TANTS -- . ~., '. -'.------'---------"------ --'- --~-~ November 5, 1990 TO: Lee Thompson FROM: David Othling Chris Kinzel SUBJECT: Silvergate Drive STOP Sign Warrant Analysis at Amarillo Road and Castilian Road This memo documents an analysis determining whether STOP signs are warranted on Silvergate Drive at Amarillo Road or Castilian Road in the City of Dublin. Vehicle and pedestrian counts were conducted manually for a total of eight hours on Thursday, November 1, 1990 at each location from 7:30 - 9:30 a.m., 11:30 - 3:30 p.m., and 4:00 - 6:00 p.m., which are the peak periods of vehicular and pedestrian activity on an average weekday. STOP signs on Silver gate Drive at Amarillo Road and Castilian Road are warranted if anyone of the three STOP sign warrants outlined in Attachment 1 are met. Since Silver gate Drive functions as a through collector street the residential area volume warrant reduction, also outlined in Attachment 1, does not apply. Amarillo Road at Silvergate Drive Warrant 1: Volume The total vehicular volume entering the intersection from. all approaches averages 335 per hour for any eight hours of an average weekday. In addition, the combined vehicular/pedestrian volume entering the intersection from Amarillo Road for the same eight hours averages 33 percent of the total vehicular volume. The average total vehicular volume per hour is 35 greater than the required minimum of 300 vehicles and the average combined vehicular/pedestrian volume from Amarillo Road is equal to the required minimum of 33 percent. Therefore, Warrant 1 is satisfied. Warrant 2: Accidents The number of accidents that have occurred within the past 12 months (1989) that might be susceptible of correction by three-way STOP sign installation totals two. i I I "'- 4637 Chabot Drive, Suite 214, Pleasantor FAX (415) 4f PLEASANTON . SACRAMENl ~l_i~~ ~~~~~~~ ',¡,,_ 'A. ""' '" ~L;¢j¡f ~ !I :=7: '- "";;:ï ,)¡ ~.01l .', 'J \~. /:~.ilt. r~~ ~~ ~ 2 ....--.. --.-...-- Lee Thompson -2- November 5, 1990 The previous 12 month accident total is three less than the required minimum of five correctable accidents. Therefore, Warrant 2 is not satisfied. Warrant 3: Visibility The straight line sight distance on the critical eastbound approach on Silvergate Drive for vehicles and pedestrians entering Silvergate Drive is 375 feet. The critical straight line sight distance is 215 feet greater than the required minimum of 160 feet. Therefore, Warrant 3 is not satisfied. Since the intersection of Amarillo Road at Silvergate Drive meets Warrant 1, 2, or 3 the installation of STOP signs at this location is warranted. Castilian Road at Silvergate Drive Warrant 1: Volume The total vehicular volume entering the intersection from all approaches averages 228 per hour for any eight hours of an average weekday. In addition, the combined vehicular/pedestrian volume entering the intersection from Castilian Road for the same eight hours averages 25 percent of the total vehicular volume. The average total vehicular volume per hour is 72 less than the required minimum of 300 vehicles and the average combined vehicular/pedestrian volume from Amarillo Road is eight percent less than the required minimum of 33 percent. Therefore, Warrant 1 is not satisfied. Warrant 2: Accidents The number of accidents that have occurred within the past 12 months (1989) that might be susceptible of correction by three-way STOP sign installation totals one. The previous 12 month accident total is four less than the required minimum of five correctable accidents. Therefore, Warrant 2 is not satisfied. Warrant 3: Visibility The straight line sight distance on the critical eastbound approach on Silvergate Drive for vehicles and pedestrians entering Silvergate Drive is 800 feet. The critical straight line sight distance is 640 feet greater than the required minimum of 160 feet. Therefore, Warrant 3 is not satisfied. Since the intersection of Castilian Road at Silvergate Drive does not meet Warrants 1,2, or 3 the installation of STOP signs at this location is not warranted. Lee Thompson -3- November 5,1990 Recommendations The Dublin City Council, responding to citizen requests, has expressed its desire to install STOP signs on Silvergate Drive at either Amarillo Road or Castilian Road. This analysis indicates that the installation of STOP signs on Silvergate Drive at Amarillo Road only, is justified. The existing 'School Xing' signs, and markings on the Silvergate Drive approaches will need to be replaced with 'Stop Ahead' signs and markings to be in compliance with state law. If STOP signs are installed on Silvergate Drive at Amarillo Road, the existing adult crossing guard would not be justified based on established warrants. A study is being conducted along the Nielsen School frontage on Amarillo Drive to identify and attempt to correct current vehicle and pedestrian safety and circulation deficiencies. The justification for transferring the adult crossing guard from Silvergate Drive to the school frontage will be investigated. On the related issue of the City Council's consideration of all-way STOP signs on Silvergate Drive at Betlen Drive, previous field inspections indicate that warrants are not met. However, the council may wish to consider the installation of STOP signs on Silvergate Drive at Betlen Drive along with STOP signs on Silvergate Drive a t Amarillo Road. ca Attachment 157-001 ATTACHMENT I WARRANTS FOR THREE-WAY STOP SIGN INSTAllATION Three-way STOP sign installation may be considered if any of the following conditions exist: WARRANT 1: VOLUME Total vehicular volume entering the intersection from all approaches must average 300 per hour for any eight hours of an average day. (24-hour equivalent approximately 4,000 vehicles.) In addition, the vehicular volume entering the intersection from the minor street or streets for the same eight hours must average at least 1/3 of the total volume entering the intersection (100 per hour minimum). WARRANT 2: ACCIDENTS Five or more of types susceptible of correction by STOP signs within a 12-month period, with satisfactory observance and enforcement ofless restrictive control. WARRANT 3: VISIBILITY The straight line sight distance on one of more approaches of the major street for vehicles or pedestrians crossing the intersection is less than 160 feet. NOTE: Volume warrants to be reduced by a 60 percent Residential Area factor if ALL of the following conditions are met: (a) Both streets have residential frontage with existing 25 miles per hour speed limits. (b) Neither street is an adopted through street. (c) Neither street exceeds 40 feet of roadway width. (d) No existing STOP sign or signal is located on the more heavily traveled street within a distance of 800 feet. (e) Intersection has three legs, with streets extending 800 feet or more away from the intersection on at least two sides. (f) Installation of a three-way STOP is compatible with overall traffic circulation needs for the residential area. 11/02/90 157-001