According to the latest Tom Tom Traffic Index, Jakarta’s traffic eased in 2018, making it the city showing the “biggest improvement” last year.

The index ranked Jakarta the seventh most congested city in the world, up from fourth place in 2017.

“Believe it or not, some cities' traffic is decreasing over time! The TomTom Traffic Index is reporting that congestion levels are decreasing in Jakarta,” the index’s Twitter account said on Friday.

Believe it or not, some cities' traffic is decreasing over time! The TomTom Traffic Index is reporting that congestion levels are decreasing in Jakarta. Find out more at: https://t.co/eulSwnAaLO #TomTomTrafficIndex pic.twitter.com/7MHhnjTovh — TomTom (@TomTom) June 13, 2019

The average congestion level in Jakarta was 53 percent in 2018, compared to 61 percent the year before.

Some Twitter users attributed the improvement to the new MRT, but the improvement was recorded before MRT Jakarta was up and running.

The TomTom Traffic index is calculated from anonymized GPS data collected via navigation devices in-dash systems and smartphones, the index says on its website.

Out of the 403 cities ranked from 56 countries on six continents, the most congested are Mumbai in India (65 percent), followed by Bogota (63 percent), Lima (58 percent), New Delhi (58 percent) and Moscow (56 percent).