I am not preview to a particular City of Long beach ordinance that addresses sign placement (it doesn't mean it doesn't exist). But you can read through the
California Manual on Uniform Traffic Control Devices (particularly Chapter 2A) which should include the standard requirements for sign placement and visibility. here's a link where you can scroll through the manual for more information:
California - FHWA MUTCD
In viewing the above manual I came across this section that I think I can use:
Section 2A.16 Standardization of Location
Support:
Standardization of position cannot always be attained in practice. Examples of heights and lateral locations
of signs for typical installations are illustrated in Figure 2A-1, and examples of locations for some typical signs
at intersections are illustrated in Figure 2A-2.
Standard:
Signs requiring different decisions by the road user shall be spaced sufficiently far apart for the
required decisions to be made reasonably safely. One of the factors considered when determining the
appropriate spacing shall be the posted or 85th-percentile speed.
Guidance:
Signs should be located on the right side of the roadway where they are easily recognized and understood by
road users. Signs in other locations should be considered only as supplementary to signs in the normal locations,
except as otherwise indicated.
Signs should be individually installed on separate posts or mountings except where:
A. One sign supplements another, or
B. Route or directional signs are grouped to clarify information to motorists, or
C. Regulatory signs that do not conflict with each other are grouped, such as turn prohibition signs posted
with one-way signs, street name signs posted with a stop or yield sign, or a parking regulation sign
posted with a speed limit sign.
Signs should be located so that they:
A. Are outside the clear zone unless placed on a breakaway or yielding support (see Section 2A.19);
B. Optimize nighttime visibility;
C. Minimize the effects of mud splatter and debris;
D. Do not obscure each other; and
E. Are not hidden from view.
Support:
The clear zone is the total roadside border area, starting at the edge of the traveled way, available for use by
errant vehicles. The width of the clear zone is dependent upon traffic volumes, speeds, and roadside geometry.
Additional information can be found in the “AASHTO Roadside Design Guide” (see Page i for AASHTO’s
address).
Guidance:
With the increase in traffic volumes and the desire to provide road users regulatory, warning, and guidance
information, an order of priority for sign installation should be established.
Then there is this also:
Section 2A.22 Maintenance
Guidance:
All traffic signs should be kept properly positioned, clean, and legible, and should have adequate
retroreflectivity. Damaged or deteriorated signs should be replaced.
To assure adequate maintenance, a schedule for inspecting (both day and night), cleaning, and replacing
signs should be established. Employees of highway, law enforcement, and other public agencies whose duties
require that they travel on the roadways should be encouraged to report any damaged, deteriorated, or obscured
signs at the first opportunity.
Steps should be taken to see that weeds, trees, shrubbery, and construction, maintenance, and utility materials
and equipment
do not obscure the face of any sign.
A regular schedule of replacement of lighting elements for illuminated signs should be maintained.
I really think this is going to be the main object of my defense if I can't get it dismissed based on the lack of a right to a speedy trial. Every time I look at the pictures I took I just don't see how a judge cannot agree that the sign was not visible due to the trees obstructing the view.