Updated

The self-proclaimed transportation of the future is running late, short and slow.

Hyperloop One Inc. is delaying and scaling back the first full test of its prototype of trainlike pods that whisk through low-pressure tubes, an event the company has held up as a historic milestone that would showcase the technology and help attract crucial future investment.

Last year, the company said it would perform the public test—which it called its “Kitty Hawk moment,” referring to the Wright brothers’ aviation milestone—before the end of 2016. It later pushed the deadline back to March 31 at the latest, which it also missed. Last month, Hyperloop One’s general counsel said at a public hearing the company plans to hold a public test of a prototype “by May or June,” several months past its original estimates.

Meanwhile, Hyperloop One has slashed the length of the test track for the prototype by more than 80%—so much that the technology won’t be able to reach the planned top speed of about 750 miles an hour, previously a key feature of the planned public display.

This story originally appeared in The Wall Street Journal.