November 21, 2017

Division Nine - Standards for Traffic Engineering - Chapter V. Line of Sight Review

Chapter V. Line of Sight Review

Sec. 905-1 Introduction

This chapter is intended as a standard for the construction and restriction of improvements in the line of sight for vehicles entering and exiting county roads as required.

Sec. 905-2 Uncontrolled Intersections

At all corners located on uncontrolled intersections no obstruction to the driver's view in excess of three feet above the adjacent gutter flowline shall be placed in a triangular area formed by the intersecting street curblines and a line connecting them at points 60 feet from the intersection point per Plate T-7.

Sec. 905-3 Alleys and Minor Driveways

No obstruction to sight view will be allowed within a triangular area formed by the alley or driveway edge and the interior sidewalk edge (the street right-of-way line if no sidewalk exists) and a line connecting them at points 10 feet from the intersection point.

Sec. 905-4 Controlled Intersections

905-4.01 Sight distance at controlled intersections shall be based upon a sight distance equal to design speed (S) in miles per hour multiplied by a factor of 10 (See Plate T-7). Design speeds for various street classifications are as follows:

 Classification  Speed (S)
 Local Street 25 MPH 
 Collector 65 MPH 
 Arterial 65 MPH 

905-4.02 Corner sight distance is measured from a point on the minor road fifteen feet from the curb line of the major road, and three feet right of the left edge of the viewing lane under consideration. Said point is 279 viewed from a height of 3.5 feet on the minor road to an oncoming vehicle height of 4.25 feet on the major road.

905-4.03 When viewing left, the location of the oncoming vehicle is considered to be twelve feet from the nearest curb line of the major street (six feet with parking prohibited). Parking is assumed to be prohibited onarterial and collector streets.

905-4.04 When viewing right, the location of the oncoming vehicle is considered to be three feet right of the left edge of the left most lane for the oncoming vehicle on the major street.

Sec. 905-5 T-Intersections

At uncontrolled T-intersections, the requirements of both Sections 905-2 and 905-4 shall be met.

Sec. 905-6 Landscaping

905-6.01 Landscaping over thirty (30) inches in height above top of curb shall not be placed within the lines of sight defined in the preceding sections. All landscaping must be maintained at a height of thirty (30) inches or less with the exception of trees as provided for in Section 905-6.02 (See Plate T-8)

905-6.02 Trees are permitted in the line of sight for controlled intersections provided that the skirt height (bottom of foliage) is maintained seven feet above the adjacent top of curb height. In the event more than one tree is placed in the sight line area they must be placed on a radial from the viewpoint. (See Plate T-8)

Location

Public Services Building
2700 M Street, Suite 570
Bakersfield, CA 93301-2370
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Phone: 661-862-5100 
FAX: 661-862-5101 
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