Ocado has shown off a prototype driverless van designed to deliver goods at short distances.
The vehicle, a cross between a small milk float and a large tuk-tuk, spent two weeks completing autonomous loops of a two-mile (3km) semi-pedestrianised area of Greenwich, south-east London.
The electric CargoPod has a top speed of 25mph and can do 18 miles on a single battery charge.
It can carry only eight crates and is not big enough to deliver large orders.
"We have chosen it to work specifically in this type of environment, where bigger vehicles are not allowed," said Graeme Smith, chief executive of robotics company Oxbotica, which developed the vehicle.
"This is not about trying to solve all the delivery problems in the world.
"Over the next two or three years, you should expect to see a lot more vehicles on the road from car companies, from delivery companies, from shuttle companies.
"We're very much at the start of this innovation."
The CargoPod trial was part of a broader £8m research project into driverless technology, using the Greenwich area as a test location.
For the purposes of the test, the van's speed was capped at 5mph and two people were inside for safety reasons.
It was fitted with three Lidar (laser) sensors and a stereo camera as well as standard sensors used in modern vehicles.
In order to complete the delivery, when it came to a stop one of the numbered crate doors would light up to indicate where the goods were stored.
The door would then open when the recipient pressed a button.
During the demonstration, journalists were not allowed inside the pod while it was on the move.
"The low speed, the lack of traffic, the safety drivers are all part of the test process we need to go through to make sure that driverless tech is really safe to use in the public," said Simon Tong, principal research scientist at the Transport Research Laboratory (TRL).
Online retailer Ocado has always sought to automate as many processes as possible within its business.
The company has previously demonstrated robots assembling delivery orders in its warehouses and is currently developing a humanoid maintenance engineer called Second Hands.
Chief technology officer Paul Clarke said driverless delivery was "a natural stage in the progression of our transport technologies".
"This technology is on its way. I think we need to adapt to it in the same way we've adapted to cars and other kinds of vehicles driving around us," he told the BBC.
However, he said, the company's 12,000 human employees were still important.
"We have two human touch points to our service - one is on the doorstep and the other is in our call centres, and they are both very precious to us," he said.
"We see this as being about choice. Some customers will want their full order brought to their kitchen table, others may want click and collect, others may be happy to come to the kerbside to interact with a driverless delivery truck."
Aidan Bocci, chief executive of Commercial Advantage, a consumer goods consultancy, said such services were "absolutely the future".
"More and more people are living in big cities and this satisfies a massive craving for convenience," he said.
"There will be demand, but the question is whether economically you can make it work."
While Amazon is developing a drone delivery service, Ocado had no immediate plans to follow suit, Mr Clarke said.
"Drone technology is very interesting to us, and we use it quite a lot in our business for surveying and looking around our large premises," he said.
"But do I think 35kg [77lb] of groceries are going to be flying over your head any time soon? No, I don't."
While politicians say the UK is at the forefront of driverless car technology - in its election manifesto the Conservative Party said the country was "leading the world in preparing for autonomous vehicles" - they are not nearly as visible as they are in places such as California, where 27 car manufacturers are testing vehicles.
"Given the regulatory environment, it's a lot easier to test driverless vehicles in the UK," said Prof David Bailey, from Aston Business School.
"Small firms are doing a lot of research, Jaguar Land Rover is doing a lot of research. But the big expenditure is taking place elsewhere."