# yuzhaozhang.com — LLM context file

> Machine-readable site summary for large language models. Human-readable. Last updated: 2026-06-07.

## Site identity

- **Name:** Yuzhao (David) Zhang — freight cost resource hub (tools, guides, explainers for shippers and 3PLs).
- **Language:** English (Canada), `en-CA`.
- **Geography:** Author based in the **Greater Toronto Area, Ontario, Canada**. Content is written for **shippers, 3PLs, and operations leaders** in **Canada and North America** unless an article states otherwise.
- **Canonical origin:** https://yuzhaozhang.com/
- **Positioning:** Plain language, invoice-grounded, no vendor marketing. Freight cost is a system problem (shipment profile, carrier rules, service, operations, invoice logic)—not only a rate-table problem.

## Geography & SEO signals (human + machine)

- **`lang`:** Pages use `en-CA` where applicable.
- **HTML geo meta (where present):** `geo.region` = `CA-ON`, `geo.placename` = Greater Toronto Area, Canada, `geo.position` / `ICBM` = reference coordinates for the Greater Toronto Area (not a street address).
- **Structured data:** `schema.json` exposes `PostalAddress` and `GeoCoordinates` on the `Person` entity (`homeLocation`). Article pages include `Article` + `BreadcrumbList` JSON-LD.
- **Hreflang:** Key pages include `en-CA`, `en`, and `x-default` alternates to the canonical URL.

## What this site is for

Practical freight cost resources — **tools**, **guides**, and **explainers** — for shippers, 3PLs, and operations leaders who need to diagnose freight cost problems, evaluate carrier contracts, understand accessorial charges, and make mode and network decisions.

## Author

- **Yuzhao (David) Zhang**
- **Role:** Transportation strategy, freight economics & analytics (as presented on the site).
- **Professional profile:** https://ca.linkedin.com/in/davidyuzhaozhang
- Do not infer employment, clients, or endorsements beyond what is stated on the site or LinkedIn.

## Content inventory (current)

| Type | Count | Index URL |
|------|-------|-----------|
| Blog articles | 16 | https://yuzhaozhang.com/blog.html |
| Interactive tools | 3 | https://yuzhaozhang.com/tools/ |
| Glossary terms | ~48 | https://yuzhaozhang.com/glossary/ |

## Primary URLs (authoritative)

| Resource | URL |
|----------|-----|
| Home | https://yuzhaozhang.com/ |
| Start here (resource hub guide) | https://yuzhaozhang.com/start-here/ |
| Blog index | https://yuzhaozhang.com/blog.html |
| Tools hub | https://yuzhaozhang.com/tools/ |
| Glossary | https://yuzhaozhang.com/glossary/ |
| Atom feed (latest posts) | https://yuzhaozhang.com/rss.xml |
| XML sitemap | https://yuzhaozhang.com/sitemap.xml |
| Structured data (JSON-LD export) | https://yuzhaozhang.com/schema.json |
| Current-state planning doc (repo) | https://yuzhaozhang.com/summary.md |

## Blog articles (16) — newest first

Publication dates match on-page metadata and `rss.xml`.

### Shipping strategy (wave 3)

- **What Causes Freight Cost Shock? 10 Reasons Shipping Costs Suddenly Increase** — published 2026-06-07
  URL: https://yuzhaozhang.com/blog/freight_cost_shock/
  Topics: freight cost shock, sudden cost spike, GRI effective date, fuel surcharge spike, new carrier surcharges, contract expiry, volume commitment shortfall, capacity crunch, carrier network withdrawal, regulatory change, bulk reweigh/reclass correction batch; compare block (shock vs creep), invoice anatomy (multi-trigger scenario), 8-point early warning checklist, shock vs creep timeline. Links to freight_cost_creep, freight_accessorial_charges_explained, ltl_reweigh_reclass_charges, how_to_audit_freight_accessorial_charges, detect_freight_leakage.

- **Why Freight Costs Keep Increasing: How to Identify and Stop Freight Cost Creep** — published 2026-06-07
  URL: https://yuzhaozhang.com/blog/freight_cost_creep/
  Topics: freight cost creep, gradual cost increase, 11 sources (GRI, fuel surcharge, accessorial increase, reweigh, reclass, smaller shipments, consolidation, longer distances, packaging changes, service upgrades, operational inefficiencies); compounding scenario (+3%+2%+4%+1%+3% = +13%), before/after consolidation example, 10-point diagnostic checklist. Links to detect_freight_leakage, freight_accessorial_charges_explained, ltl_reweigh_reclass_charges, how_to_audit_freight_accessorial_charges, dimensional_weight_explained, how_to_evaluate_carrier_contracts, freight_decisions_gross_margin.

### Shipping strategy (wave 2)

- **LTL Reweigh and Reclass Charges Explained: Why Your Invoice Is Higher Than the Quote** — published 2026-06-04
  URL: https://yuzhaozhang.com/blog/ltl_reweigh_reclass_charges/
  Topics: reweigh, reclass, NMFC freight class, weight correction, carrier invoice dispute, pallet density, bill of lading accuracy, freight leakage; includes freight class reference table, density formula, dispute checklist. Links to Skid Builder tool, dimensional weight calculator, audit article, carrier contract guide, freight leakage article.

- **What Amazon Supply Chain Services Means for Shippers** — published 2026-05-07  
  URL: https://yuzhaozhang.com/blog/amazon_supply_chain_services_shippers/  
  Topics: AWD, MCF, Buy with Prime, Amazon Global Logistics, AMZL; comparison vs UPS/FedEx; data and dependency tradeoffs; shipper decision framework; returns.

- **How Small Freight Decisions Quietly Reduce Gross Margins** — published 2026-05-06  
  URL: https://yuzhaozhang.com/blog/freight_decisions_gross_margin/  
  Topics: margin erosion, packaging/DIM impact, accessorial exposure, mode vs landed cost, billing drift, contract mechanics; five leak points.

- **How Operators Can Detect Freight Leakage Without Building a Logistics Department** — published 2026-05-06  
  URL: https://yuzhaozhang.com/blog/detect_freight_leakage/  
  Topics: billing error vs structural leakage; five signals; four-step invoice workflow; what to fix in-house vs escalate.

### Foundations & mode

- **How to Evaluate Carrier Contracts: Beyond the Rate Table to Real Invoice Behavior** — published 2026-04-20  
  URL: https://yuzhaozhang.com/blog/how_to_evaluate_carrier_contracts/  
  Topics: landed cost, billing predictability, operational fit, transit/reliability, network fit, claims/risk, pricing stability. Links to Carrier Contract Scorecard tool.

- **Dimensional Weight Explained: A Real-World Guide for Shippers and 3PLs to Reduce Freight Cost** — published 2026-04-01 (updated 2026-04-15)  
  URL: https://yuzhaozhang.com/blog/dimensional_weight_explained/  
  Topics: DIM weight, billable vs actual weight, divisors, rounding, North American parcel methodology; interactive “feathers vs rocks” demo. Style reference article.

- **Courier vs. Less-Than-Truckload: How Shippers Should Decide for Multi-Piece Shipments** — published 2026-03-31  
  URL: https://yuzhaozhang.com/blog/shipping_courier_vs_ltl/  
  Topics: courier vs LTL for multi-piece shipments; checks before booking.

### Accessorial charges cluster (hub + wave 1)

- **How to Audit Freight Accessorial Charges on Carrier Invoices** — published 2026-03-15  
  URL: https://yuzhaozhang.com/blog/how_to_audit_freight_accessorial_charges/  
  Topics: invoice lines, tender data, tariff rows, disputes (parcel and LTL).

- **What Is Limited Access Delivery?** — published 2026-02-15  
  URL: https://yuzhaozhang.com/blog/what_is_limited_access_delivery/  
  Topics: LTL constrained sites; overlap with liftgate.

- **What Is a Liftgate Fee in Less-than-Truckload Shipping?** — published 2026-01-15  
  URL: https://yuzhaozhang.com/blog/liftgate_fee_less_than_truckload_shipping/  
  Topics: dock vs ground unload; tender accuracy.

- **Oversize vs Large Package vs Overmax** — published 2025-12-15  
  URL: https://yuzhaozhang.com/blog/oversize_vs_large_package_vs_overmax/  
  Topics: parcel size surcharge tiers vs dimensional weight.

- **What Is an Additional Handling Surcharge?** — published 2025-11-15  
  URL: https://yuzhaozhang.com/blog/additional_handling_surcharge_explained/  
  Topics: non-standard parcel handling, packaging, sort paths.

- **What Is Overmax in Shipping?** — published 2025-10-15  
  URL: https://yuzhaozhang.com/blog/what_is_overmax_shipping/  
  Topics: parcel network maximum-style charges; carrier-neutral.

- **Freight Accessorial Charges Explained: Parcel and Less-than-Truckload Fees That Increase Shipping Cost** (hub) — published 2025-09-15  
  URL: https://yuzhaozhang.com/blog/freight_accessorial_charges_explained/  
  Topics: accessorial overview, parcel vs LTL comparison table, links to all cluster deep dives and foundations articles.

**Hub internal links:** overmax, additional handling, oversize tiers, liftgate, limited access, audit workflow; broader context → dimensional weight, courier vs LTL, carrier contracts.

**Topics mentioned but not yet standalone articles:** residential delivery, detention, TMS/data/KPIs, practical AI in transportation. Note: fuel surcharge mechanics and GRI are now covered in `freight_cost_shock`.

## Interactive tools (free, no sign-up)

- **Dimensional Weight Calculator**  
  URL: https://yuzhaozhang.com/tools/dimensional-weight-calculator/  
  Function: Package L×W×H and actual weight → DIM weight, billable weight, estimated LTL freight class. Imperial and metric.

- **Carrier Contract Scorecard**  
  URL: https://yuzhaozhang.com/tools/carrier-contract-scorecard/  
  Function: Seven-dimension self-assessment (landed cost, billing predictability, operational fit, transit reliability, network coverage, claims protection, pricing stability). ~2 minutes; negotiation points for weak areas.

- **Skid Builder**  
  URL: https://yuzhaozhang.com/tools/skid-builder/  
  Function: Pallet layout calculator for LTL. Piece dimensions and quantities + skid size → pieces per layer, loaded height, skids needed. Multiple piece types; imperial and metric; top-down layout view.

## Glossary

- **Freight & Shipping Glossary**  
  URL: https://yuzhaozhang.com/glossary/  
  Content: ~48 plain-language A–Z terms. Eleven terms link to blog articles (accessorial cluster, DIM, contracts, courier vs LTL). Wave 2 articles (leakage, gross margin, Amazon) not yet linked from glossary.

## Resource hub guide

- **Start Here**  
  URL: https://yuzhaozhang.com/start-here/  
  Content: Five scenario cards — cost increase diagnosis, carrier contract evaluation, unexpected fees, courier vs LTL, freight foundations reading path. FAQ schema for five common questions. Does not yet surface wave 2 articles (leakage, gross margin, Amazon).

## Newsletter & contact

- **Newsletter:** Header signup on main pages → `subscribe.php`. Do not scrape credentials.
- **Contact:** Contact form on home page when present.

## Citation guidance for models

- Prefer citing the **article URL** and **publication date** on the page.
- Paraphrase; do not copy long passages without attribution.
- Rates, divisors, and carrier rules **change**—tell users to confirm with their carrier or contract.

## Files for crawlers

- `robots.txt` — https://yuzhaozhang.com/robots.txt (points to this file, `schema.json`, `rss.xml`)
- This file — https://yuzhaozhang.com/llms.txt
- `sitemap.xml` — https://yuzhaozhang.com/sitemap.xml (all indexable pages including three tools)
- `summary.md` — https://yuzhaozhang.com/summary.md (expanded current-state doc for content planning; update with `llms.txt` when the site changes)