
Quoting
gundog10
Here you go...

Quoting
Page 19 of the above (docs.google) document
Notes & Recommendations
The MUTCD 2003 California Supplement recommends the speed limit be set at the first 5 MPH increment below the critical speed. First 5 MPH increment below the critical speed is 30 MPH. Staff recommends the current 30 MPH posted speed limit to be retained. 40% of accidents occured due to unsafe speed manuevers and this segment is located next to college campus with 25 mph speed zone.
That is ALL incorrect.
Here's a link to the MUTCD 2003 California Supplement . Look at page 2B-51 and you'll find the rules you're looking for.

Quoting
from Page 2B-51 of the MUTCD 2003 California Supplement
The speed limit should be established at the nearest 10 km/h (5 mph) increment to the 85th percentile speed. However, in matching existing conditions with the traffic safety needs of the community, engineering judgement may indicate the need for a further reduction of 10 km/h (5 mph).
The underlined portion (from page 19 of the report) should read as follows:
The MUTCD 2003 California Supplement recommends the speed limit be set at the first 5 MPH increment nearest the critical speed. The Critical (85%) speed in 38mph. First 5 MPH increment nearest the critical speed is 40mph.
Assuming that a further reduction can be justified by way of the reasons they cited (high accident rate and "speed continuity" from the adjacent 25mph zone), the 40mph result can then be further reduced by 5mph.... Which would have resulted in a justified posted speed limit of 35mph... They posted it at 30.
Just on that alone, you should be able to successfully argue that the engineer erred in his conclusion, by misinterpreting the standard recommended procedure (per the 2003 CA MUTCD), and therefore enforcement of an unjustified speed limit, constitutes a "speed trap" pursuant to VC sections 40801 - 40802.
ETA: The information I referenced from the document you posted was from table "A-3".