CarParts.com Targets 300,000 In-House Deliveries: Build a Last-Mile Insourcing Gate

CarParts.com plans to bring a meaningful share of final-mile delivery under its own control. The headline target—300,000 packages a year through an internal network—sounds like a fleet-expansion story. Operationally, it is a route-economics story.

According to Supply Chain Dive, CEO David Meniane described the potential savings as “substantial” as the company scales toward that annual volume. But insourcing does not become economical merely because total volume is large. The packages must appear in the right ZIP codes, on compatible days, with enough contribution margin to cover vehicles, drivers, insurance, dispatch, failed stops, and backup capacity.

Auto parts make that decision unusually important. A bumper, hood, fender, or grille can be light relative to its dimensions, difficult to automate, expensive to repackage, and vulnerable to cosmetic damage. Parcel pricing can punish dimensional weight, while rough handling can turn a completed delivery into a replacement shipment and a disappointed customer. An internal route may avoid some of those costs, but only when shipment density supports it.

Start with the real cost per successful delivery

Comparing a carrier invoice with a driver's wage produces a dangerously incomplete answer. The outsourced cost should include base transportation, residential and oversized surcharges, peak fees, claims, replacement freight, customer-service work, and revenue lost when damage or delay causes cancellation.

The internal cost should include vehicle lease or depreciation, fuel or charging, maintenance, insurance, driver wages and benefits, recruiting, dispatch, routing technology, loading labor, parking, tolls, uniforms, handheld devices, and management overhead. Divide that total by successful deliveries, not dispatched packages. A route with 30 stops and four failed deliveries has a different cost base from one with 30 completed stops.

Use a common contribution formula at the shipment level:

Delivery contribution = order margin − pick and pack cost − expected delivery cost − expected damage and recovery cost − failed-delivery cost.

That makes the tradeoff visible. An internal fleet may cost slightly more per first attempt yet win after lower damage, faster recovery, and fewer service contacts. Conversely, an apparently full truck may still destroy margin if stops are geographically scattered or vehicle capacity is consumed by awkward freight before the route reaches enough addresses.

Set a ZIP-level density gate

Annual volume is useful for budgeting, but routes live by day and geography. Three hundred thousand packages spread evenly across 250 operating days equals roughly 1,200 packages per day. That still says nothing about whether a particular depot can build an efficient route.

Create a rolling eight- to twelve-week view by origin facility, destination ZIP, promised date, product cube, handling class, margin, and delivery outcome. For every candidate zone, measure stops per route hour, miles per successful stop, packages per stop, vehicle cube utilization, on-time rate, failed-attempt rate, and damage cost per package.

Management should approve an internal route only when the zone clears explicit thresholds for several consecutive weeks. A workable gate might require sufficient daily stops to cover fixed route cost, positive contribution after a conservative failure allowance, a maximum number of miles per stop, and a stable base of eligible bulky products. The exact thresholds belong to CarParts.com's own cost structure; the discipline is to publish them before adding vehicles.

Density should also be tested by day of week. A ZIP cluster that supports a full route on Monday and Thursday may not justify seven-day internal service. In that case, schedule internal delivery on dense days and retain carrier service on thin days rather than forcing utilization.

Protect the customer promise

Speed can be a genuine advantage. Earlier network expansion helped CarParts.com reduce average delivery time from nine days to one or two days, Supply Chain Dive reported in 2022. An internal fleet could give the company tighter control over dispatch, handling, proof of delivery, and exception recovery.

However, checkout promises must reflect actual capacity. The order-management system should reserve route space before showing an internal-delivery date. Eligibility rules should consider origin inventory, cutoff time, product dimensions, customer ZIP, route capacity, delivery restrictions, and driver hours. Once capacity reaches a defined ceiling, the system should offer the next internal date or tender the package to an approved carrier.

Do not let a routing project silently change customer service. Track promised-versus-actual delivery, ETA accuracy, first-attempt success, damage, claims, cancellations, and contacts per order for internal and outsourced shipments. Segment results by product family and zone; averages can hide a poor experience for the bulkiest, most valuable items.

Keep a carrier fallback alive

Insourcing reduces dependence on parcel networks, but it creates exposure to vehicle breakdowns, driver absences, weather, volume spikes, and local operating disruptions. The answer is not total independence. It is a controlled allocation model.

Maintain carrier rates, labels, pickup arrangements, packaging rules, and electronic connections for every internal zone. Define automatic overflow triggers such as route capacity above 90%, an unfilled driver shift, a vehicle outage, forecast volume beyond a peak threshold, or a delivery promise that the fleet cannot safely meet. Assign each trigger an owner and a decision deadline.

The wider parcel market is not standing still. Supply Chain Dive reported that Amazon's U.S. parcel deliveries rose 9.7% in the first half of 2026 from the prior-year period as the company relied less on UPS and expanded rural coverage. The lesson is not that every shipper should copy Amazon. It is that delivery portfolios are becoming more dynamic, and shippers need the data and integrations to shift volume without disrupting customers.

Scale through four evidence gates

Gate 1: Model. Use at least eight weeks of shipment history to identify candidate ZIP clusters. Include the full cost of failures and damage, then stress-test fuel, wage, insurance, and volume assumptions.

Gate 2: Pilot. Launch a limited number of routes from one facility. Cap daily volume, preserve carrier fallback, and compare internal shipments with a similar outsourced control group.

Gate 3: Stabilize. Expand only after the pilot meets contribution, on-time, damage, first-attempt, safety, and customer-contact thresholds for several consecutive weeks. Investigate the tail of poor routes rather than relying on the network average.

Gate 4: Replicate. Recalculate the economics for every new market. A playbook can transfer; density, labor availability, parking, tolls, and customer geography cannot.

The strongest last-mile strategy is not “own” or “outsource.” It is a governed decision that assigns each package to the option most likely to protect margin and the customer promise. With ZIP-level density, shipment-level contribution, capacity controls, and a live carrier fallback, 300,000 deliveries can become a scalable operating capability instead of an expensive fleet target.

Ready to make route allocation and carrier fallback decisions with better shipment data? Request a CXTMS demo to see how CXTMS supports transportation planning, execution, and exception visibility.