On 13 May, the Rio state Transportation Secretary Rodrigo Vieira said that the $2.8bn 16km-long Line 4 metro extension that will connect to the city’s Olympic Park and Athletes Village will open on 1 August – just four days before the 2016 Olympic Games starts.

The announcement is a further embarrassment for Brazil as it struggles with its preparations for the games thanks to an economy that is locked in recession, a president that has been impeached, and an outbreak of the mosquito-borne Zika Virus.

Two days earlier on 11 May, Dubai’s Roads and Transport Authority (RTA) opened final offers from two shortlisted bidders for the contract to design and build the new metro link – known as Route 2020 – that will connect to the Expo 2020 site.

Eerily there are two similarities between the two projects. The lowest offer submitted by a team of Spain’s Acciona, Turkey’s Gulermak, and France’s Alstom is $2.7bn – almost the same as the cost of the Rio project, and the line is 15km long, just 1km short of the Rio line.

Dubai will be hoping that is where the similarities end. The Dubai Expo opens on 20 October 2020, which gives more than four years for the metro line to be completed. If all goes to plan that should be more than enough time to complete the project, but if things go wrong, as they have in Brazil, then timing will be tight – construction work on Line 4 started five and a half years ago in October 2010.

It is perhaps with this in mind that the two groups shortlisted contain companies that have delivered rail projects in Dubai before. Alstom completed the Dubai Tram in 2014, and Mitsubishi Heavy Industries and Obayashi, both Japanese, opened the Red and Green Lines of Dubai Metro in 2009 and 2010.

Like the Olympics, the Expo attracts global attention and Dubai will be keen to avoid any negative publicity.