At $860 million last year, the global autonomous delivery market seems quite large, yet it remains in its infancy.

A new report from consultancy MarketsandMarkets predicts the sector will grow to $4.9 billion by 2030, growing at a 21.5% compound annual growth rate. The report, “Autonomous Last Mile Delivery Market by Platform,” cited the advancement of sense and avoid systems in aerial delivery drones, expansion of e-commerce and increased use of low-cost and light payload drones by startups for product delivery.

The report breaks the growth down by platform, combining ground delivery vehicles such as self-driving trucks and vans and delivery robots into one group and cargo and delivery drones into another.

Use of autonomous vehicles, regardless of platform, could reduce last-mile delivery costs for the retail industry between 80% and 90%, the report suggested.