Determination Letter — JOSH-2026-HILLS-GATEWAY-37_8914-n122

26.1

Max ΔT (min)

2.25

Threshold (min)

DISCRETIONARY
REVIEW REQUIRED

Controlling FindingControlling finding: Marin Avenue adds 26.06 min of marginal evacuation clearance time — 11.6× the 2.25-min threshold (45 min × 5%, Very High FHSZ, NIST TN 2135). Exceeds threshold by 23.81 min.

Analysis

Applicability Threshold

Minimum 15 dwelling units — integer comparison, no discretion

IN SCOPE

80 dwelling units proposed ≥ 15-unit threshold. Project size threshold: 15 dwelling units (ITE Trip Generation de minimis; SB 330, Gov. Code §65913.4).

Site Parameters

CAL FIRE FHSZ classification — sets road capacity degradation factor and ΔT threshold for clearance analysis

VERY HIGH FHSZ

Project site: Zone 3 (Very High) (source: CAL FIRE OSFM)
CAL FIRE HAZ_CLASS: 3 — vhfhsz; road capacity reduced to 0.35× HCM base (composite engineering-judgment factor anchored against HCM 2022 Ch. 11 weather CAF framework + NIST TN 2135 Camp Fire empirical observations; independent traffic-engineering review pending).
ΔT threshold: reduced proportionally (shorter safe egress window applies; see Clearance Analysis below).
Mobilization rate: 0.90 (NFPA 1660 / 1616 community mass-evacuation design basis, constant — unaffected by FHSZ zone; ~10% zero-vehicle HH per Census ACS B25044).

Evacuation Clearance Analysis

Route identification (0.5 mi radius) + per-path ΔT test — this is the operative determination step

EXCEEDS THRESHOLD

240 serving route segments within 0.5 mi (OSM evacuation route network).

ΔT threshold: 45 min safe egress window (NIST TN 2135, Very High FHSZ) × 5% max project share = 2.25 min

About the route list. The routes listed below are paths evacuees may self-select during an evacuation (User Equilibrium). The determination uses the controlling (worst-case) route because some evacuees will take it — slower routes do not "fix" faster ones. See §3.6 and §8.6 of the Legal Defensibility Memo for the full methodology.

13 routes evaluated; controlling ΔT = 26.06 min on Marin Avenue.

Project vehicles: 137 (units × 1.9 vpu × 0.90 mobilization; NFPA 1660 / 1616 community mass-evacuation design basis, Census ACS B25044 zero-vehicle adjustment). Effective capacity = HCM 2022 raw × 0.35 composite hazard-degradation factor. Routes sorted fastest exit first (User Equilibrium ordering).

Path	Bottleneck Segment	FHSZ Zone	Eff. Cap (vph)	Exit (min)	ΔT (min)	Threshold	Margin
proj_100565801_243670952 CONTROLLING	Marin Avenue Two-lane · 20 mph · 2 ln → HCM 900 × 0.35 = 315 vph	Very High FHSZ	315	—	26.06	2.25	+23.81
proj_100565801_2644106915	Shasta Road Two-lane · 25 mph · 2 ln → HCM 1,125 × 0.35 = 394 vph	Very High FHSZ	394	—	20.85	2.25	+18.60
proj_100565801_2644106917	Shasta Road Two-lane · 25 mph · 2 ln → HCM 1,125 × 0.35 = 394 vph	Very High FHSZ	394	—	20.85	2.25	+18.60
proj_100565801_52982359	Marin Avenue Two-lane · 20 mph · 2 ln → HCM 900 × 0.35 = 315 vph	Very High FHSZ	315	—	26.06	2.25	+23.81
proj_100565801_35833153	Marin Avenue Two-lane · 20 mph · 2 ln → HCM 900 × 0.35 = 315 vph	Very High FHSZ	315	—	26.06	2.25	+23.81
proj_100565801_86276581	Marin Avenue Two-lane · 20 mph · 2 ln → HCM 900 × 0.35 = 315 vph	Very High FHSZ	315	—	26.06	2.25	+23.81
proj_100565801_52982363	Marin Avenue Two-lane · 20 mph · 2 ln → HCM 900 × 0.35 = 315 vph	Very High FHSZ	315	—	26.06	2.25	+23.81
proj_100565801_53013480	Marin Avenue Two-lane · 20 mph · 2 ln → HCM 900 × 0.35 = 315 vph	Very High FHSZ	315	—	26.06	2.25	+23.81
proj_100565801_52995575	Marin Avenue Two-lane · 20 mph · 2 ln → HCM 900 × 0.35 = 315 vph	Very High FHSZ	315	—	26.06	2.25	+23.81
proj_100565801_53011243	Marin Avenue Two-lane · 20 mph · 2 ln → HCM 900 × 0.35 = 315 vph	Very High FHSZ	315	—	26.06	2.25	+23.81
proj_100565801_1635557750	Marin Avenue Two-lane · 20 mph · 2 ln → HCM 900 × 0.35 = 315 vph	Very High FHSZ	315	—	26.06	2.25	+23.81
proj_100565801_1541561262	Shasta Road Two-lane · 25 mph · 2 ln → HCM 1,125 × 0.35 = 394 vph	Very High FHSZ	394	—	20.85	2.25	+18.60
proj_100565801_1895821107	Shasta Road Two-lane · 25 mph · 2 ln → HCM 1,125 × 0.35 = 394 vph	Very High FHSZ	394	—	20.85	2.25	+18.60

SB 79 Transit Proximity

Transit stop within 0.5 mi — does not affect this determination

INFORMATIONAL

Determination

DETERMINATION →

Project meets the 15-unit applicability threshold and 13 serving path(s) exceed the ΔT threshold of 2.25 min (max ΔT: 26.1 min). FHSZ Zone 3 (vhfhsz) — road capacity degradation applied. Behavioral mobilization: 0.90 (FHWA, constant). Discretionary review required. Legal basis: AB 747 (California Government Code §65302.15) — General Plan Safety Element mandatory update for evacuation route capacity analysis; HCM 2022 (Highway Capacity Manual, 7th Edition) — effective capacity with hazard degradation; NFPA 101 (Life Safety Code) — 0.90 mobilization design basis (100% occupant evacuation, adjusted for ~10% zero-vehicle households per Census ACS B25044); NIST TN 2135 (Maranghides et al.) — safe egress windows by hazard zone.

Wildland Evacuation Analysis: DISCRETIONARY

SB 79 Transit Proximity (Informational): NOT APPLICABLE

Required Next Steps

This project requires discretionary review under AB 747 (Gov. Code §65302.15). The objective standards analysis has determined that this project would add more than 2.25 minutes of marginal evacuation clearance time (ΔT) on one or more serving evacuation paths in hazard zone vhfhsz (maximum ΔT: 26.06 min vs. 2.25-min threshold).

ΔT exceedance identified on 13 path(s): Path proj_100565801_243670952 — bottleneck: Marin Avenue (ΔT 26.1 min vs 2.25-min threshold); Path proj_100565801_2644106915 — bottleneck: Shasta Road (ΔT 20.9 min vs 2.25-min threshold); Path proj_100565801_2644106917 — bottleneck: Shasta Road (ΔT 20.9 min vs 2.25-min threshold); and 10 more paths

Environmental Impact Report (EIR) required under CEQA (Pub. Resources Code §21100) — evacuation clearance time impact must be analyzed as a significant transportation impact.
Evacuation Clearance Time Analysis: Applicant shall commission a study conforming to the JOSH v4.0 ΔT methodology (AB 747 / Gov. Code §65302.15), analyzing marginal evacuation clearance time on all serving paths within 0.5 miles, using NFPA 1660 / 1616 community mass-evacuation design basis mobilization rate (0.90 constant) and HCM 2022 hazard-degraded capacity factors (HCM Ch. 11 weather CAF framework with WUI fire-condition composite adjustment).
Public Hearing before the Planning Commission is required prior to any project approval (Gov. Code §65905).
Fire Department Review: Submit project plans to the Fire Marshal for review of evacuation access, egress widths, and compliance with Fire Code §503.
Mitigation Measures or Project Redesign: Applicant must demonstrate — through the clearance time analysis — either (a) that mitigation measures reduce ΔT below 2.25 minutes on all serving paths, or (b) that the project scope (units, stories, or both) is reduced to fall within the ΔT threshold, to qualify for ministerial review.
Approval is not ministerial until the ΔT exceedance is mitigated or the project is redesigned to fall within the ΔT threshold on all serving evacuation paths.

Legal Authority

Every numerical value in this determination is derived mechanically from the authorities below. No engineering judgment was exercised. The same methodology is applied uniformly to all projects under AB 747.

#	Authority	Published / Adopted	Parameter	Value Applied
1	AB 747, Gov. Code §65302.15	2021 Ch. 394	Analysis mandate	—
2	CAL FIRE OSFM FHSZ (state-adopted SRA map)	Current SRA designation	Hazard zone	`vhfhsz` — Zone 3 (Very High)
3	NIST TN 2135 (Maranghides et al., Camp Fire)	2021	Safe egress window (Very High FHSZ)	45 min
4	Standard engineering significance criterion	—	Maximum project share of egress window	5%
→	Derived from ③ × ④		ΔT threshold for this location	45 × 0.05 = 2.25 min
5	HCM 2022 Exhibit 12-7 (TRB 7th Ed.)	TRB 2022	Road HCM base capacity (controlling: Marin Avenue Two-lane, 20 mph, 2 lanes)	900 vph
6	Composite hazard-degradation factor — anchored against HCM 2022 Ch. 11 weather CAF framework + NIST TN 2135 Camp Fire empirical observations; independent traffic-engineering review pending (FSC May 2026)	TRB 2022 / NIST 2021 / FSC 2026	Hazard capacity degradation (Very High FHSZ)	0.35×
→	Derived from ⑤ × ⑥		Effective bottleneck capacity	315 vph
7	NFPA 1660 Standard for Emergency, Continuity, and Crisis Management (2024 ed.; consolidates NFPA 1616 Mass Evacuation, Sheltering, and Re-entry Programs, 2020 ed.)	NFPA 2024 / 2020	Community mass-evacuation mobilization rate (design basis)	0.90 (constant)
8	U.S. Census ACS B25044	2020 5-yr	Zero-vehicle household adjustment (~10%)	Incorporated in NFPA 1660 / 1616 mobilization constant
→	Formula result		ΔT (marginal evacuation clearance time)	26.06 min vs. 2.25-min limit

Core Formula

ΔT = (project_vehicles / bottleneck_effective_capacity_vph) × 60 + egress_penalty
project_vehicles = 80 units × 1.9 vpu × 0.90 (NFPA 1660 / 1616 mobilization constant) = 137 vph
egress_penalty = 0 (building < 4 stories)
Flagged when ΔT > 2.25 min (threshold = 45 min × 5%)

This determination applies the above authorities mechanically. No engineering judgment was exercised. The same methodology is applied uniformly to all projects under AB 747.

▶ determination_37_8914_n122_2494_80u.txt

======================================================================
FIRE EVACUATION CAPACITY ANALYSIS  -  PROJECT DETERMINATION
JOSH v4.0 (dT Standard  -  Constant Mobilization, NFPA 101)
======================================================================
Date:           2026-05-27T02:57:02.341946
Project:        Hills Gateway
Address:        Claremont Ave & Tunnel Rd
APN:            Not provided
Location:       37.8914, -122.2494
Dwelling Units: 80
Stories:        3

ALGORITHM
----------------------------------------
  Universal 5-Step Evacuation Capacity Algorithm v4.0 (dT Standard  -  constant mobilization)
  Each scenario applies: (1) applicability check, (2) scale gate, (3) route identification (EvacuationPath objects with bottleneck tracking), (4) demand calculation (behavioral_mobilization 0.90 x vpu x units  -  FHWA constant), (5) dT test (project_vehicles / bottleneck_effective_capacity x 60 + egress). FHSZ affects road capacity degradation only  -  not mobilization. Most restrictive tier across all applicable scenarios is the final determination.
  Reference: See legal.md for full legal basis and defense reference.

======================================================================
SCENARIO: WILDLAND_AB747
  Legal Basis: AB 747 (California Government Code Sec.65302.15)  -  General Plan Safety Element mandatory update for evacuation route capacity analysis; HCM 2022 (Highway Capacity Manual, 7th Edition)  -  effective capacity with hazard degradation; NFPA 101 (Life Safety Code)  -  0.90 mobilization design basis (100% occupant evacuation, adjusted for ~10% zero-vehicle households per Census ACS B25044); NIST TN 2135 (Maranghides et al.)  -  safe egress windows by hazard zone
  Result: DISCRETIONARY  |  Triggered: YES
======================================================================

  STEP 1  -  APPLICABILITY CHECK (Standard 3: FHSZ Modifier)
  --------------------------------------
  Method: Always applicable; site FHSZ check via GIS point-in-polygon
  Result: APPLICABLE
  Note: FHSZ Zone 3 (vhfhsz)  -  road capacity degradation applied; mobilization unaffected. Behavioral mobilization 0.90 (FHWA, constant).
  Standard 3 (FHSZ): Zone 3 (Very High) [HAZ_CLASS=3]  hazard_zone=vhfhsz  (IN FIRE ZONE)
  Behavioral Mobilization: 0.90 (FHWA Emergency Transportation Operations  -  mandatory evacuation compliance rate)

  STEP 2  -  SCALE GATE (Standard 1)
  --------------------------------------
  80 >= 15 -> TRIGGERED
  (80 units vs. 15 threshold)

  STEP 3  -  ROUTE IDENTIFICATION (Standard 2)
  --------------------------------------
  Method: Project-origin Dijkstra (v4.0, travel-time weight)  -  fastest path from project site to each regional-network exit node (motorway/trunk/primary at city boundary); weight=length/speed_limit (seconds) per speed_defaults config; 29 nodes within 0.5 mi network zone; respects road barriers (I-5, rail, etc.)
  Radius: 0.5 miles (804.7 m)
  Serving route segments found: 240
  Serving EvacuationPaths identified: 13
    - Eastshore Freeway: eff_cap=11250 vph, fhsz=non_fhsz, deg=1.00, vc=0.500 (informational)
    - Gilman Street: eff_cap=1900 vph, fhsz=non_fhsz, deg=1.00, vc=0.400 (informational)
    - Hopkins Street: eff_cap=3800 vph, fhsz=non_fhsz, deg=1.00, vc=6.777 (informational)
    - La Loma Avenue: eff_cap=562 vph, fhsz=high_fhsz, deg=0.50, vc=1.509 (informational)
    - Grizzly Peak Boulevard: eff_cap=394 vph, fhsz=vhfhsz, deg=0.35, vc=0.250 (informational)
    - Cedar Street: eff_cap=1125 vph, fhsz=non_fhsz, deg=1.00, vc=3.345 (informational)
    - Marin Avenue: eff_cap=315 vph, fhsz=vhfhsz, deg=0.35, vc=4.425 (informational)
    - Shasta Road: eff_cap=394 vph, fhsz=vhfhsz, deg=0.35, vc=0.250 (informational)
    - The Circle: eff_cap=1900 vph, fhsz=non_fhsz, deg=1.00, vc=2.556 (informational)
    - Ashby Avenue: eff_cap=7600 vph, fhsz=non_fhsz, deg=1.00, vc=3.095 (informational)
    - Shattuck Avenue: eff_cap=7600 vph, fhsz=non_fhsz, deg=1.00, vc=0.400 (informational)
    - Monterey Avenue: eff_cap=3800 vph, fhsz=non_fhsz, deg=1.00, vc=1.757 (informational)
    - Quail Avenue: eff_cap=394 vph, fhsz=vhfhsz, deg=0.35, vc=0.250 (informational)
    - Campus Drive: eff_cap=394 vph, fhsz=vhfhsz, deg=0.35, vc=0.250 (informational)
    - Queens Road: eff_cap=394 vph, fhsz=vhfhsz, deg=0.35, vc=0.250 (informational)
    - Glendale Avenue: eff_cap=394 vph, fhsz=vhfhsz, deg=0.35, vc=0.250 (informational)
    - San Pablo Avenue: eff_cap=3800 vph, fhsz=non_fhsz, deg=1.00, vc=0.280 (informational)
    - University Avenue: eff_cap=3800 vph, fhsz=non_fhsz, deg=1.00, vc=0.178 (informational)
    - Adeline Street: eff_cap=3800 vph, fhsz=non_fhsz, deg=1.00, vc=0.719 (informational)
    - 1296429668: eff_cap=3800 vph, fhsz=non_fhsz, deg=1.00, vc=0.400 (informational)
    - 6320410: eff_cap=2250 vph, fhsz=non_fhsz, deg=1.00, vc=4.388 (informational)
    - 430174911: eff_cap=900 vph, fhsz=non_fhsz, deg=1.00, vc=1.887 (informational)

  STEP 4  -  DEMAND CALCULATION
  --------------------------------------
  Formula: 80 x 1.9 x 0.90
  Hazard Zone: vhfhsz
  Behavioral Mobilization: 0.90 (FHWA Emergency Transportation Operations, constant)
  Project vehicles (peak hour): 136.8 vph
  Source (vehicles/unit): U.S. Census ACS B25044
  Source (mobilization): FHWA Emergency Transportation Operations  -  mandatory evacuation compliance rate for residential areas (0.90). vehicles_per_unit already reflects zero-vehicle households via ACS B25044 all-household average.

  STEP 5  -  dT TEST (Standard 4)
  --------------------------------------
  Method: dT = (project_vehicles / bottleneck_effective_capacity) x 60 + egress
  Hazard Zone: vhfhsz
  Behavioral Mobilization: 0.90 (FHWA Emergency Transportation Operations, constant)
  Project Vehicles: 136.8 vph
  Egress Penalty: 0.0 min (NFPA 101/IBC; applies to buildings >= 4 stories)
  Safe Egress Window: 45 min (vhfhsz, NIST TN 2135)
  Max Project Share:  5%
  dT Threshold:       2.25 min (45 min window x 5%, NIST TN 2135)
  Paths Evaluated: 13
  Max dT: 26.06 min
  Triggered: YES  -  DISCRETIONARY

  Per-Path Results (all evaluated paths  -  no deduplication):
    Path proj_100565801_243670952  |  origin BG: project_origin  |  65 segments
    Bottleneck: Marin Avenue (Shattuck Avenue to The Circle), 1.2 mi W *** dT EXCEEDS THRESHOLD  -  DISCRETIONARY ***
      Road: Two-lane highway  |  Speed: 20 mph  |  Lanes: 2  |  HAZ_CLASS: 3 (vhfhsz)
      HCM cap: 900 vph  x degradation 0.35 (vhfhsz)  = eff cap 315 vph
      dT = (136.8 vph / 315 vph) x 60 + 0.0 min egress = 26.06 min  (threshold: 2.25 min (45 min x 5%))

    Path proj_100565801_2644106915  |  origin BG: project_origin  |  74 segments
    Bottleneck: Shasta Road (Hill Road to Grizzly Peak Boulevard), 0.2 mi W *** dT EXCEEDS THRESHOLD  -  DISCRETIONARY ***
      Road: Two-lane highway  |  Speed: 25 mph  |  Lanes: 2  |  HAZ_CLASS: 3 (vhfhsz)
      HCM cap: 1125 vph  x degradation 0.35 (vhfhsz)  = eff cap 394 vph
      dT = (136.8 vph / 394 vph) x 60 + 0.0 min egress = 20.85 min  (threshold: 2.25 min (45 min x 5%))

    Path proj_100565801_2644106917  |  origin BG: project_origin  |  73 segments
    Bottleneck: Shasta Road (Hill Road to Grizzly Peak Boulevard), 0.2 mi W *** dT EXCEEDS THRESHOLD  -  DISCRETIONARY ***
      Road: Two-lane highway  |  Speed: 25 mph  |  Lanes: 2  |  HAZ_CLASS: 3 (vhfhsz)
      HCM cap: 1125 vph  x degradation 0.35 (vhfhsz)  = eff cap 394 vph
      dT = (136.8 vph / 394 vph) x 60 + 0.0 min egress = 20.85 min  (threshold: 2.25 min (45 min x 5%))

    Path proj_100565801_52982359  |  origin BG: project_origin  |  78 segments
    Bottleneck: Marin Avenue (Shattuck Avenue to The Circle), 1.2 mi W *** dT EXCEEDS THRESHOLD  -  DISCRETIONARY ***
      Road: Two-lane highway  |  Speed: 20 mph  |  Lanes: 2  |  HAZ_CLASS: 3 (vhfhsz)
      HCM cap: 900 vph  x degradation 0.35 (vhfhsz)  = eff cap 315 vph
      dT = (136.8 vph / 315 vph) x 60 + 0.0 min egress = 26.06 min  (threshold: 2.25 min (45 min x 5%))

    Path proj_100565801_35833153  |  origin BG: project_origin  |  78 segments
    Bottleneck: Marin Avenue (Shattuck Avenue to The Circle), 1.2 mi W *** dT EXCEEDS THRESHOLD  -  DISCRETIONARY ***
      Road: Two-lane highway  |  Speed: 20 mph  |  Lanes: 2  |  HAZ_CLASS: 3 (vhfhsz)
      HCM cap: 900 vph  x degradation 0.35 (vhfhsz)  = eff cap 315 vph
      dT = (136.8 vph / 315 vph) x 60 + 0.0 min egress = 26.06 min  (threshold: 2.25 min (45 min x 5%))

    Path proj_100565801_86276581  |  origin BG: project_origin  |  77 segments
    Bottleneck: Marin Avenue (Shattuck Avenue to The Circle), 1.2 mi W *** dT EXCEEDS THRESHOLD  -  DISCRETIONARY ***
      Road: Two-lane highway  |  Speed: 20 mph  |  Lanes: 2  |  HAZ_CLASS: 3 (vhfhsz)
      HCM cap: 900 vph  x degradation 0.35 (vhfhsz)  = eff cap 315 vph
      dT = (136.8 vph / 315 vph) x 60 + 0.0 min egress = 26.06 min  (threshold: 2.25 min (45 min x 5%))

    Path proj_100565801_52982363  |  origin BG: project_origin  |  80 segments
    Bottleneck: Marin Avenue (Shattuck Avenue to The Circle), 1.2 mi W *** dT EXCEEDS THRESHOLD  -  DISCRETIONARY ***
      Road: Two-lane highway  |  Speed: 20 mph  |  Lanes: 2  |  HAZ_CLASS: 3 (vhfhsz)
      HCM cap: 900 vph  x degradation 0.35 (vhfhsz)  = eff cap 315 vph
      dT = (136.8 vph / 315 vph) x 60 + 0.0 min egress = 26.06 min  (threshold: 2.25 min (45 min x 5%))

    Path proj_100565801_53013480  |  origin BG: project_origin  |  81 segments
    Bottleneck: Marin Avenue (Shattuck Avenue to The Circle), 1.2 mi W *** dT EXCEEDS THRESHOLD  -  DISCRETIONARY ***
      Road: Two-lane highway  |  Speed: 20 mph  |  Lanes: 2  |  HAZ_CLASS: 3 (vhfhsz)
      HCM cap: 900 vph  x degradation 0.35 (vhfhsz)  = eff cap 315 vph
      dT = (136.8 vph / 315 vph) x 60 + 0.0 min egress = 26.06 min  (threshold: 2.25 min (45 min x 5%))

    Path proj_100565801_52995575  |  origin BG: project_origin  |  82 segments
    Bottleneck: Marin Avenue (Shattuck Avenue to The Circle), 1.2 mi W *** dT EXCEEDS THRESHOLD  -  DISCRETIONARY ***
      Road: Two-lane highway  |  Speed: 20 mph  |  Lanes: 2  |  HAZ_CLASS: 3 (vhfhsz)
      HCM cap: 900 vph  x degradation 0.35 (vhfhsz)  = eff cap 315 vph
      dT = (136.8 vph / 315 vph) x 60 + 0.0 min egress = 26.06 min  (threshold: 2.25 min (45 min x 5%))

    Path proj_100565801_53011243  |  origin BG: project_origin  |  83 segments
    Bottleneck: Marin Avenue (Shattuck Avenue to The Circle), 1.2 mi W *** dT EXCEEDS THRESHOLD  -  DISCRETIONARY ***
      Road: Two-lane highway  |  Speed: 20 mph  |  Lanes: 2  |  HAZ_CLASS: 3 (vhfhsz)
      HCM cap: 900 vph  x degradation 0.35 (vhfhsz)  = eff cap 315 vph
      dT = (136.8 vph / 315 vph) x 60 + 0.0 min egress = 26.06 min  (threshold: 2.25 min (45 min x 5%))

    Path proj_100565801_1635557750  |  origin BG: project_origin  |  75 segments
    Bottleneck: Marin Avenue (Shattuck Avenue to The Circle), 1.2 mi W *** dT EXCEEDS THRESHOLD  -  DISCRETIONARY ***
      Road: Two-lane highway  |  Speed: 20 mph  |  Lanes: 2  |  HAZ_CLASS: 3 (vhfhsz)
      HCM cap: 900 vph  x degradation 0.35 (vhfhsz)  = eff cap 315 vph
      dT = (136.8 vph / 315 vph) x 60 + 0.0 min egress = 26.06 min  (threshold: 2.25 min (45 min x 5%))

    Path proj_100565801_1541561262  |  origin BG: project_origin  |  58 segments
    Bottleneck: Shasta Road (Hill Road to Grizzly Peak Boulevard), 0.2 mi W *** dT EXCEEDS THRESHOLD  -  DISCRETIONARY ***
      Road: Two-lane highway  |  Speed: 25 mph  |  Lanes: 2  |  HAZ_CLASS: 3 (vhfhsz)
      HCM cap: 1125 vph  x degradation 0.35 (vhfhsz)  = eff cap 394 vph
      dT = (136.8 vph / 394 vph) x 60 + 0.0 min egress = 20.85 min  (threshold: 2.25 min (45 min x 5%))

    Path proj_100565801_1895821107  |  origin BG: project_origin  |  59 segments
    Bottleneck: Shasta Road (Hill Road to Grizzly Peak Boulevard), 0.2 mi W *** dT EXCEEDS THRESHOLD  -  DISCRETIONARY ***
      Road: Two-lane highway  |  Speed: 25 mph  |  Lanes: 2  |  HAZ_CLASS: 3 (vhfhsz)
      HCM cap: 1125 vph  x degradation 0.35 (vhfhsz)  = eff cap 394 vph
      dT = (136.8 vph / 394 vph) x 60 + 0.0 min egress = 20.85 min  (threshold: 2.25 min (45 min x 5%))


  -> Scenario Tier: DISCRETIONARY
  Reason: Project meets the 15-unit applicability threshold and 13 serving path(s) exceed the dT threshold of 2.25 min (max dT: 26.1 min). FHSZ Zone 3 (vhfhsz)  -  road capacity degradation applied. Behavioral mobilization: 0.90 (FHWA, constant). Discretionary review required. Legal basis: AB 747 (California Government Code Sec.65302.15)  -  General Plan Safety Element mandatory update for evacuation route capacity analysis; HCM 2022 (Highway Capacity Manual, 7th Edition)  -  effective capacity with hazard degradation; NFPA 101 (Life Safety Code)  -  0.90 mobilization design basis (100% occupant evacuation, adjusted for ~10% zero-vehicle households per Census ACS B25044); NIST TN 2135 (Maranghides et al.)  -  safe egress windows by hazard zone.

======================================================================
SCENARIO: SB79_TRANSIT
  Legal Basis: SB 79 (2025)  -  objective health and safety standard carve-out for by-right projects (transit proximity context); California Public Utilities Code Sec.21155 (Tier 1/2 transit)
  Result: NOT_APPLICABLE  |  Triggered: NO
======================================================================
  NOT APPLICABLE: SB 79: project is not within 0.5 miles of Tier 1/2 transit. Informational only  -  no tier impact.
  SB 79 Transit Proximity: outside transit buffer

======================================================================
FINAL DETERMINATION
======================================================================
  RESULT: DISCRETIONARY REVIEW REQUIRED

  Project meets the 15-unit applicability threshold and 13 serving path(s) exceed the dT threshold of 2.25 min (max dT: 26.1 min). FHSZ Zone 3 (vhfhsz)  -  road capacity degradation applied. Behavioral mobilization: 0.90 (FHWA, constant). Discretionary review required. Legal basis: AB 747 (California Government Code Sec.65302.15)  -  General Plan Safety Element mandatory update for evacuation route capacity analysis; HCM 2022 (Highway Capacity Manual, 7th Edition)  -  effective capacity with hazard degradation; NFPA 101 (Life Safety Code)  -  0.90 mobilization design basis (100% occupant evacuation, adjusted for ~10% zero-vehicle households per Census ACS B25044); NIST TN 2135 (Maranghides et al.)  -  safe egress windows by hazard zone.

  PARAMETERS APPLIED
  --------------------------------------
  Hazard Zone:        vhfhsz
  Behavioral Mobilization: 0.90 (FHWA Emergency Transportation Operations  -  mandatory evacuation compliance rate)
  Vehicles per Unit:  1.9 (U.S. Census ACS B25044, CA statewide all-HH average)
  Egress Penalty:     0.0 min (NFPA 101/IBC  -  3 stories)
  Safe Egress Window: 45 min (vhfhsz, per NIST TN 2135)
  Max Project Share:  5%
  dT Threshold:       2.25 min (45 x 5%)
  Max dT (project):   26.06 min

  Determination Tier:
    DISCRETIONARY REVIEW REQUIRED

  At least one scenario triggered DISCRETIONARY: the project meets the
  dwelling unit size threshold and at least one serving path's dT exceeds
  the applicable threshold for the project's hazard zone.

  dT = (project_vehicles / bottleneck_effective_capacity) x 60 + egress_penalty
  The baseline state of the road is irrelevant  -  projects in already-failing
  zones are tested equally (key v3.0 correction from v2.0 marginal causation test).

  NOTE: Fire zone location (Standard 3) affects mobilization rate and dT threshold;
  it does not independently gate the determination.

  Scenario Tier Summary:
    wildland_ab747: DISCRETIONARY
    sb79_transit: NOT_APPLICABLE

  Aggregation Logic: Most restrictive tier across all applicable scenarios wins.
  Tier Ranking: DISCRETIONARY(3) > MINISTERIAL WITH STANDARD CONDITIONS(2) > MINISTERIAL(1) > NOT_APPLICABLE(0)

  This determination is based solely on objective, verifiable criteria.
  No professional discretion was applied. All calculations are reproducible.
  See legal.md for full legal basis and defense reference.
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Scope & Limitations

Civilian outbound capacity only. JOSH measures the ΔT contribution of civilian vehicles exiting the project on its serving evacuation routes. Concurrent emergency apparatus inbound access, required by CCR 1273.00 of the 2025 California Wildland-Urban Interface Code (CWUIC) adopted by the State Fire Marshal, requires separate analysis that is outside the scope of this determination.

Screening tool, not denial instrument. Consistent with CWUIC Appendix C §C101.6, ΔT provides an initial idealized order-of-magnitude clearance estimate intended to trigger further review under the Housing Accountability Act safety exception (Gov. Code §65589.5(j)(1)). It is not a substitute for a full community evacuation study and is not a standalone permit-denial instrument.

Methodology open items (independent traffic-engineering review by Fire Science Consulting LLC, May 2026): hazard-degradation factor empirical derivation; CWUIC road-geometry pre-check (CWUIC §§403.1, 403.3 — 20-ft / 26-ft minimums); shadow-evacuation and cumulative route capacity tracking; δt(egress) for low-rise (IBC 2024 Ch. 10 + SFPE Handbook Ch. 64).

Appeal Rights

This determination is the result of an objective, algorithmic analysis under adopted city standards. All inputs, calculations, and threshold comparisons are recorded in the attached audit trail and are fully reproducible.

An applicant who disagrees with this determination may appeal within 10 business days of the date of this letter to the City of Berkeley Planning Commission. The appeal must identify a specific factual error in the data inputs or threshold parameters. Engineering judgment is not a basis for appeal — these are objective standards.

For questions, contact the Planning Department. Reference the case number on this letter.