Although it has promised that “traffic and congestion will be a thing of the past,” videos emerging from demonstrations at the Consumer Electronics Show (CES) in Las Vegas show that traffic and congestion are still possible in the Boring Company’s tunnels.

In a video published by Benjamin Brochstein on a demonstration ride in Tesla and the Boring Company’s Las Vegas loop, a traffic jam can be seen forming outside of the Las Vegas Convention Center.

As you’d expect because of your experience with traffic above ground, the jam forms near the point where Teslas leave the main roadway. Since there is only one lane that each vehicle must leave and rejoin in order to let passengers off, traffic slows as passengers wait for their turn to be let out.

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In the video, the vehicle operator explains that the traffic occurs because not all of the entrances to the convention center are open, forcing everyone to be let off at just one of a few locations. Although this is not an demonstration of the system working perfectly, it is an example of exactly the kind of inconvenience that all traffic systems face.

To critics, that’s the issue with single-lane tunnels for cars, like the one Tesla has built in Las Vegas. It takes a good idea that already exists, building transportation infrastructure underground (like a subway or metro), and makes it much less efficient by reducing the number of people it can handle.

Though they reduce the cost on cities, which don’t have to pay for the trains and conductors, they shift that cost onto passengers who have to pay for their Tesla, making it useful only to those who can afford it. It doesn’t take a degree in economics to see that that creates a two-tier transportation network that is less useful to cities and the majority of people who live there.

As this video that was highlighted by Vice proves, although it intends to create a luxury transportation network, much like the other infrastructure systems that have preceded it, congestion remains an issue. Though they promise much, these tunnels show evidence of familiar transportation issues even when they are being used by a small number of visitors in an environment built specifically to highlight their advantages.