In many metropolises, the congestion and delay of rail transit have brought about tremendous psychological stress to commuters and considerable economic loss to the society. For example, according to a report by the Ministry of Land, Infrastructure, Transport and Tourism of Japan, on an average, train delays (more than 5 min) were observed for 45 railway lines in the Tokyo metropolitan area in 11.7 days of 20 weekdays in a month, and more than half of the short delays (within 10 min) were caused by extended dwell time (MLIT, 2020). Kariyazaki et al (2015) estimated that in Japan, train delays resulted in social cost in excess of 1.8 billion dollars per year. In a high-frequency operated rail transit system, when a train delay occurs because of either an accident or extended dwell time, the subsequent trains are forced to decelerate or stop between stations to maintain a safety clearance, which is a so-called "knock-on delay" on the rail track (Carey and Kwieci nski, 1994). Meanwhile, more passengers are kept waiting on the platform when trains decelerate or stop (because headways of trains are extended), which results in a longer dwell time of trains.

Amazon already knows a lot about its users, thanks to the plethora of data gathered from Alexa-equipped devices and the millions of purchases made on the e-commerce site. But soon, the tech giant's AI could be able to do more than just predict users' morning commute or notify them when they run out of toilet paper. Amazon is in the process of developing a voice-activated wearable device that can recognize human emotions using a variety of signals, Bloomberg reported. Soon, Amazon's AI could be able to do more than just predict users' morning commute. The device would be worn on a wrist and could be equipped with microphones and voice-detection software that allow it to interpret human emotions.

Finally, a solution for our increasingly congested roads is on the horizon. In last week's Huawei Connect conference, Shenzhen's Traffic Police Technology Chief Li Quiang announced the launch of their Traffic Brain system. Shenzhen is basically like the "Silicon Valley of Hardware", with some of the world's largest hardware manufacturers and tech companies setting up shop there. So it's no surprise that one of the most advanced traffic management systems in the world is being rolled out there first. This traffic management system represents some seriously advanced tech.

Over the next four weeks, BBC News will be offering a snapshot of the day in the life of a city - looking at how technology is transforming our urban landscapes, now and in the future. We will look at how technology is improving the morning commute, what it is doing to make our working day better, how it will transform our evening's entertainment and what goes on at night in the smart cities that increasingly never sleep. We start as urban dwellers around the world begin the day - with the morning commute. In the future, that may mean hailing a jetpack. "Jetpacks will be part of future cities," Peter Coker, vice-president of innovation at KuangChi Science, Martin Aircraft Company's major Chinese shareholder.