research atlas - City of Los Angeles - v0 screening

Neighborhood arterial tunnel candidate screening

This atlas identifies surface streets that may be functioning as freeway access, freeway bypass, or ramp-to-ramp throughways. The policy concept is not to add general road capacity. It is to remove non-local vehicle pressure from selected neighborhood arterials, then redesign the surface street for walking, biking, transit, slower speeds, trees, loading, and local access.

21 v0 corridors screened as research hypotheses

10 non-reject corridors in the top shortlist

5 commercial/transit main-street controls explicitly rejected

screening standard

A candidate means "study this," not "build this."

The ranking below is a decision-support starting point. It encodes the research plan: identify likely through-traffic pressure, connect it to freeway behavior, measure neighborhood harm, test surface redesign upside, and then punish any corridor with commercial-main-street, transit, portal, geology, equity, or induced-demand risks.

interactive route map

Surface pressure versus tunnel-study alignments

Orange lines mark existing congested surface corridors. Cyan etched lines show simplified tunnel-bypass concepts for screening discussion only.

street reclamation rendering

Existing congestion versus low-traffic redesign

Select a corridor above to update the street section and conceptual tunnel portal locations.

existing condition

High-throughput arterial pressure

traffic role: regional access mixing with local frontage
street feel: fast, noisy, hard to cross

surface after bypass

Low-traffic multimodal boulevard

surface priority: local access, walking, biking, transit, trees
operating speed: slow local circulation

portal A

Conceptual entry portal

Portal should be placed outside the most sensitive neighborhood frontage, with surface lanes reclaimed immediately after the through movement dives underground.

lat/lng pending selection

portal B

Conceptual exit portal

Exit portal should reconnect through traffic near freeway-facing geometry while protecting bus stops, sidewalks, loading, and local-only circulation above.

lat/lng pending selection

typology map

Final labels used in the screen

7 Freeway access funnel

3 Freeway parallel bypass

2 Ramp-to-ramp neighborhood cut-through

2 Canyon/pass connector

2 Industrial freight pressure corridor

5 Reject: commercial/transit main street

scoring logic

Six signals, with fatal flaws subtracting from the score.

score = 0.22 through traffic + 0.20 freeway relationship + 0.20 neighborhood harm + 0.18 surface redesign upside + 0.12 tunnel feasibility - 0.18 fatal-flaw risk

Scores are intentionally conservative. A corridor with high congestion but strong commercial frontage or transit-main-street value can rank lower than a less famous corridor with clearer freeway-access behavior and better surface-redesign payoff.

top shortlist

Ten corridors for deeper data collection

Cahuenga / Highland funnel

Hollywood Bowl, Highland Ave, Cahuenga Pass, US-101 ramps

72 Freeway access funnel / medium-high confidence

existing surface-street problem: Strong ramp proximity, canyon geometry, event surges, and visible conflict between regional access and local Hollywood pedestrian movement.
tunnel bypass concept: Short bored bypass from the Hollywood grid to a portal north of the most neighborhood-facing ramp throat.
surface redesign concept: Reclaim Highland/Cahuenga edges for bus priority, protected walking zones, event loading, and slower local access.
fatal-flaw risks: Complex portals near the Bowl, US-101 structures, utilities, event operations, and historic/cultural frontage.

Sepulveda Pass local pressure

Sepulveda Blvd between Westwood, Sherman Oaks, and I-405 interfaces

67 Freeway parallel bypass / medium-high confidence

existing surface-street problem: Parallel to a major PeMS-monitored freeway bottleneck corridor and likely receives diversion during I-405 breakdowns.
tunnel bypass concept: Study only as a targeted local-through bypass, not as a second freeway. Coordinate with Sepulveda transit planning.
surface redesign concept: Transit priority, protected bike/walk segments where feasible, local access management, and slower speeds near institutions.
fatal-flaw risks: Very high capital cost, transit project conflicts, induced demand, seismic/geology complexity, and portal land control.

Barham / Cahuenga connector

Burbank edge, Universal City, Hollywood Freeway interface

66 Ramp-to-ramp neighborhood cut-through / medium confidence

existing surface-street problem: Connector geometry, freeway adjacency, and a surface corridor doing both regional access and local neighborhood work.
tunnel bypass concept: Short connector tunnel to keep freeway-bound movements away from neighborhood-facing surface curves.
surface redesign concept: Safer crossings, local lane discipline, bus stop upgrades, and speed reduction through the studio/residential edge.
fatal-flaw risks: Jurisdiction edges, studio operations, portal geometry, and US-101 interchange constraints.

Laurel Canyon south approach

Hollywood to Studio City via Laurel Canyon Blvd

65 Canyon/pass connector / medium confidence

existing surface-street problem: Classic pass connector with constrained right-of-way, steep grades, neighborhood frontage, and regional pressure between basin and Valley.
tunnel bypass concept: Canyon bypass for longer-distance hill crossing traffic, with surface retained for residents, emergency access, and low-speed local trips.
surface redesign concept: Traffic calming, safer shoulders, walking refuges, turn management, and hillside stormwater/landscape repair.
fatal-flaw risks: Geology, fire evacuation, portal siting, emergency egress, and neighborhood acceptance are major feasibility gates.

Alameda industrial freight spine

Downtown industrial edge to Vernon/port-oriented freight approaches

65 Industrial freight pressure corridor / medium confidence

existing surface-street problem: Heavy goods movement, freeway/rail adjacency, high environmental burden, and repeated pedestrian exposure at industrial edges.
tunnel bypass concept: Freight-biased bypass or grade-separated truck movement where neighborhood exposure is highest.
surface redesign concept: Truck conflict reduction, protected worker crossings, bus stops, trees where possible, and industrial loading order.
fatal-flaw risks: Contaminated soils, rail interfaces, freight operations, ventilation, and equity concerns around concentrating truck flows.

Glendale / Hyperion / Fletcher

Silver Lake, Atwater, Elysian Valley, I-5/CA-2 interfaces

65 Freeway access funnel / medium confidence

existing surface-street problem: Bridge/ramp geometry and narrow neighborhood interfaces suggest through movements competing with local public realm.
tunnel bypass concept: Targeted bypass of freeway-bound traffic between river crossings and ramp zones.
surface redesign concept: River-adjacent bike/walk continuity, safer crossings, local retail access, and traffic calming.
fatal-flaw risks: River crossings, bridge structures, portal space, and active commercial frontage require careful exclusion screening.

Lincoln Blvd airport/coastal approach

LAX edge, Westchester, Playa Vista, Venice-adjacent approaches

62 Freeway access funnel / medium confidence

existing surface-street problem: Airport demand, freeway connections, and through movement pressure on surface commercial/residential edges.
tunnel bypass concept: Airport-access bypass segment where regional trips overwhelm local frontage, coordinated with LAX access planning.
surface redesign concept: Protected bike lanes, bus priority, slower airport-edge streets, safer crossings, and local loading zones.
fatal-flaw risks: Airport security, coastal constraints, commercial frontage, transit corridors, and portal right-of-way.

Slauson / Florence freight-access bands

South LA industrial/residential interfaces and I-110/I-405/I-710 approach logic

62 Industrial freight pressure corridor / low confidence

existing surface-street problem: High environmental-justice sensitivity and likely freight/commuter pressure on arterials near freeway access networks.
tunnel bypass concept: Freight diversion or grade-separated goods movement only after equity and air-quality analysis.
surface redesign concept: Safer crossings, bus islands, protected bike links, shade, traffic calming, and local truck-route discipline.
fatal-flaw risks: Could worsen pollution concentration if ventilation, tolling, and truck routing are not designed around equity first.

La Cienega north-south pressure

West Adams, Mid-City, Beverly Grove, I-10/I-405 access patterns

61 Freeway parallel bypass / medium confidence

existing surface-street problem: Major north-south arterial connecting freeway zones and job centers with significant neighborhood crossing burden.
tunnel bypass concept: Only study discontinuous bypass segments where the street is acting as regional access, not where it is a commercial main street.
surface redesign concept: Bus priority, safer crossings, loading management, protected bike options on parallel streets, and slower local traffic.
fatal-flaw risks: Commercial frontage, transit priority, dense utilities, station-area conflicts, and likely induced-demand critique.

Manchester / Century airport-access bands

South LA, Westchester, LAX east/south approaches

60 Freeway access funnel / low confidence

existing surface-street problem: Airport and freeway access likely create non-local traffic pressure on neighborhood arterials.
tunnel bypass concept: Airport-access tunnel only if paired with LAX demand management and surface safety commitments.
surface redesign concept: Bus priority, pedestrian safety, local access, shade, and traffic calming near residential frontage.
fatal-flaw risks: Airport planning, environmental justice, ventilation, and induced-demand concerns.

ranked atlas

All v0 corridor hypotheses

Rank	Corridor	Type	Score	Through	Freeway	Harm	Redesign	Fatal
01	Cahuenga / Highland funnelHollywood Bowl, Highland Ave, Cahuenga Pass, US-101 ramps	Freeway access funnel	72	90	96	82	78	22
02	Sepulveda Pass local pressureSepulveda Blvd between Westwood, Sherman Oaks, and I-405 interfaces	Freeway parallel bypass	67	84	98	72	70	24
03	Barham / Cahuenga connectorBurbank edge, Universal City, Hollywood Freeway interface	Ramp-to-ramp neighborhood cut-through	66	82	90	74	66	20
04	Laurel Canyon south approachHollywood to Studio City via Laurel Canyon Blvd	Canyon/pass connector	65	88	74	86	72	25
05	Alameda industrial freight spineDowntown industrial edge to Vernon/port-oriented freight approaches	Industrial freight pressure corridor	65	78	82	80	62	18
06	Glendale / Hyperion / FletcherSilver Lake, Atwater, Elysian Valley, I-5/CA-2 interfaces	Freeway access funnel	65	76	84	70	80	21
07	Lincoln Blvd airport/coastal approachLAX edge, Westchester, Playa Vista, Venice-adjacent approaches	Freeway access funnel	62	76	78	74	78	28
08	Slauson / Florence freight-access bandsSouth LA industrial/residential interfaces and I-110/I-405/I-710 approach logic	Industrial freight pressure corridor	62	72	76	88	66	24
09	La Cienega north-south pressureWest Adams, Mid-City, Beverly Grove, I-10/I-405 access patterns	Freeway parallel bypass	61	80	82	76	72	34
10	Manchester / Century airport-access bandsSouth LA, Westchester, LAX east/south approaches	Freeway access funnel	60	72	76	82	74	34
11	Reseda north-south arterial pressureSan Fernando Valley, US-101/SR-118 access fields, residential and commercial frontage	Freeway access funnel	59	68	70	62	76	18
12	Vermont Ave transit corridorHollywood, Koreatown, South LA, multiple freeway crossings	Reject: commercial/transit main street	57	70	74	86	92	68
13	Bundy / Centinela / Barrington access gridWest LA, Brentwood/Mar Vista/Sawtelle, I-10/I-405 interfaces	Ramp-to-ramp neighborhood cut-through	57	68	78	66	70	28
14	Western Ave basin spineHollywood to South LA, multiple freeway crossings and dense transit frontage	Reject: commercial/transit main street	56	72	72	78	84	55
15	Venice Blvd main-street segmentsMid-City, Palms, Mar Vista, Venice approaches	Reject: commercial/transit main street	56	72	70	78	86	62
16	Olympic / Pico paired corridorsWestside to Downtown paired one-way/arterial pressure zones	Freeway parallel bypass	56	78	76	74	70	46
17	Crenshaw / La Brea diagonal pressureMid-City, Baldwin Hills, Inglewood-edge approaches	Freeway access funnel	56	70	66	76	78	38
18	Riverside / Los Feliz / Griffith Park edgeLos Feliz, Griffith Park, I-5/SR-134/US-101 influence zone	Freeway access funnel	56	66	74	68	76	32
19	Figueroa north/south segmentsHighland Park, Downtown edges, South LA, multiple freeway crossings	Reject: commercial/transit main street	55	68	72	78	88	58
20	Santa Monica Blvd west/central segmentsHollywood, West Hollywood edge, West LA interfaces	Reject: commercial/transit main street	53	70	68	76	86	60
21	Foothill / Sunland-Tujunga accessNortheast Valley edge, I-210/SR-118 approaches and hillside communities	Canyon/pass connector	52	62	64	58	62	20

validation plan

How the v0 atlas becomes an evidence-backed screen

Pull recent traffic counts. Confirm whether each top-20 corridor has LADOT ADT, turning, or volume-speed survey data from the last 10 years.
Connect surface pressure to freeway behavior. Compare AM/PM directionality against Caltrans PeMS bottlenecks, ramp geometry, and incident periods.
Run fatal-flaw review. Manually verify commercial frontage, transit corridor status, schools, parks, historic resources, portals, utilities, and equity risks.
Test controls. Keep Vermont, Venice, Western, Santa Monica, and Figueroa as reject/control cases so the method does not simply rank every busy street.
Require surface-space reclamation. Reject any tunnel concept that does not remove or calm surface vehicle capacity and fund local safety improvements.