This week, startup Hyperloop Transportation Technologies (otherwise known as HyperloopTT) announced that it would start building a commercial Hyperloop track as well as an "XO Square Innovation Center" and a "Hyperloop Experience Center" in Abu Dhabi, capitol city of the United Arab Emirates. Construction will commence in the third quarter of 2019, HyperloopTT claimed.

The news seems to extend an agreement made public in April . That's when HyperloopTT and a state-controlled real-estate developer announced the acquisition of a construction site where a six-mile (10km) commercial track would be built from Abu Dhabi, with the hopes of reaching Dubai.

HyperloopTT and its competing startup, Virgin Hyperloop One, have attracted $31.2 million and $196.2 million in investment, respectively. Both startups regularly conduct feasibility studies for hyperloop systems in locations across the globe, and they announce agreements with governments eager to cash in on hyperloop's theoretical potential.

But neither startup has publicly demonstrated a speed record, and technical details from either company on how their 720 mile-per-hour levitating train would handle curves and braking when filled with passengers are slim. Hyperloop TT is also still building its first test track in Toulouse, France. Virgin Hyperloop One has a test track in Nevada, but little news from that track has been shared in recent months.

Earlier this month, HyperloopTT announced a prototype of a commercial passenger pod, covered in sensors to enhance safety (although the effectiveness of the pod or its sensors is still to be determined).

For this new project in Abu Dhabi, HyperloopTT received an investment from international design group Dar Al-Handasah, which will help build the HyperloopTT commercial track and peripheral buildings. Dar Al-Handasah will rely on architecture, engineering, and cost-management firms from the US, Spain, and the UK. HyperloopTT is unique in that it was started as more-or-less a volunteer effort by engineers and scientists around the world.

Virgin Hyperloop One has a competing agreement to build a test track in neighboring Dubai, which is the most populous city in the UAE. In 2016, that startup said it would have a "Kitty Hawk" demonstration in 2017, and its promotional materials projected a functional Hyperloop by 2020. Such a demonstration did not occur in 2017, and it's unclear if Virgin Hyperloop One will keep its "fully functional" date promise.