From: Mark Nelson (Home Gmail)
To: CityClerk
Cc: Chadwick B. Castle; Brad Waller; Paige Kaluderovic; James Light; Scott Behrendt; Zein Obagi; Andrew Winje; Darryl Boyd Subject: Public Comment on Redondo Beach Capital Budget Item BRR#03 - Soundwall for 500-600 N Prospect Frontage Date: Wednesday, June 4, 2025 10:08:37 AM
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Mayor and Council:
The Punch Line: RBPWs Estimated $3M cost of the Prospect frontage soundwall should be $500K Because Budget Request Responses (BRRs) BRR#03 and BRR#22 relevant to the Frontage road neighborhood were not presented by RBPW at the meeting on 6/3/25, my 3-minute public comment time was used primarily to explain the reasons for the BRRs and the RBPW responses. CM Obagi noted that this was the first that he'd been made aware of the Prospect frontage issue so it was time well spent, but 3- minutes was too short given the complex material and issues.
Unfortunately, 4 of the 8 residents of the Frontage road that attended the meeting were unable to stay late enough to offer their public comments after the staff budget discussion on other items.
In order to assure the understanding of the Council, I am providing a recap of my public testimony from June 3, 2025 with the advantage of more than 3-minutes of speaking time and a few written comments.
Budget Request Response #03 - What's the cost of a soundwall for Prospect frontage road? RBPW Response
Option 1: 24-foot tall x 1050-foot long soundwall would be $3.13M Option 2: 8-foot tall x 1050-foot long iron fence with a guardrail would be $974K (Note: Guardrail alone would be $112K and would provide some safety from yet another auto speeding off of big Prospect and rolling onto the Frontage.)
Why 24-feet tall?
We don't know. A reasonable question from the Council and public is: Why is the soundwall 24-feet tall? The California Highway Standards Manual states soundwalls are a minimum 6-feet and maximum 14-feet.
Since RBPW suggested 8-feet tall for the fence, why isn't the soundwall 8-feet tall to at least be inside State manual standards?
Is the cost per square foot estimate accurate?
No. RBPW calculated a per square foot (psf) cost of a soundwall using contractor bids sent to Caltrans last year. RBPWs cost estimate was $68.22 psf +/- $64.18 (1 standard deviation). Statistically speaking, that is poor quality statistical estimate interpreted as "68% of the time, the cost will fall between $4.04 and $132.40 per square foot". Stat 101's advice would be to go look at the data.
A little digging into Caltrans data showed that it included a bid for a 304 sf wall. Most walls were thousands or tens-of-thousands of square feet. Bids for that very small wall were up to 800% higher than for typical walls and it doesn't represent the proposed 25,000 sf soundwall size at all. Statistically, that's called an outlier.
After removing it and recalculating the average per square foot cost of a soundwall using Caltrans data, the result was $32.23 psf +/- $6.07 (1 std dev). That is high quality statistical estimate interpreted as "68% of the time, the cost will fall between $26.16 and $38.30 psf".
What is a better total estimated cost for the soundwall? The City's formula for estimating the cost of the soundwall is to add 35% to the contractor's bid cost for City costs, and then add another 35% on for inflation. The resulting math with a good quality per square foot cost estimate and using the City's own 8-foot height based on the iron fence height it proposed is under $500K:
That's a long, long way from BRR#03's estimated cost of $3,133,139.94.
What do I recommend?
I have previously communicated with RBPW and recommended they withdraw BRR#03 results and replace them with a higher quality estimate that the public can review and comment on. For Council decision making, I recommend to discard the BRR#03 $3M estimate and replace it with the fully documented $500K estimate above.