Traffic routing in the ever-changing city of Doha

APRIL 2021 | VOL. 64 | NO. 4 | COMMUNICATIONS OF THE ACM 67 P H O T O B Y P H I L I P L A N G E /S H U T T E R S T O C K .C O M that lasted 10 minutes yesterday, could last 25 minutes today. Cab drivers in the city of Doha (Qatar’s capital), who are mostly foreigners, also wish they could rely on popular navigation services such as Google Maps, Here, or Tomtom. Yet, all such systems fall short in coping up with the rapid urbanization and the ever-changing roads in Doha. This was actually depicted in a very popular caricature in one of the most widely distributed daily local newspapers showing Google maps as a limping turtle that is helplessly trying to catch a bunny representing the road changes in the city of Doha. Besides the general public who is not happy with the routes offered by navigation systems, other stakeholders from public and private sectors were struggling with the poor quality of existing digital maps. For example, the Ministry of Transport and Communication was facing issues getting access to the most accurate map of the road network, needed for their traffic modeling. Also, transportation, delivery, and logistics companies that heavily rely on accurate maps, routes, and travel time estimates were tired of the many lost drivers and missed rendezvous. Early work: Silent maps are not enough. The issue of inaccurate local maps has triggered an early work at Qatar Computing Research Institute (QCRI) in collabospeed, fare, route, as well as sampled GPS points for each trip—a gold mine for our research agenda. But most importantly, we also learned from our partners about the real challenges they face, which helped us prioritize our projects. Map enrichments for traffic-aware routing. Our first project with Karwa was to enrich the topological maps with traffic information, that is, accurate edge weights for each road segment for each hour of the day. Inferring traffic information from a large number of vehicles can be relatively straightforward. However, the problem is much more challenging when the data is sparse and does not cover many roads with large frequency. We tackle these problems in Stanojevic et al. and derive a traffic layer with an accuracy comparable to the commercial maps using only sparse data available to us either from Karwa Taxi data as in Stanojevic et al. or from using commercial map APIs as in Stanojevic et ration with Qatar Mobility Innovation Center (QMIC) to come up with an accurate map for the city of Doha, Qatar. The idea was to use data collected from a fleet of vehicles that are continuously tracked, for accurate and timely detection of road changes, such as new roads, road closures, and detours. Though that early work was successful in coming up with a more accurate map than what navigation systems have, it was not enough to address the main problem of routing. Accurate topological maps do not say much about the time needed to go through each road segment—a main functionality needed for any routing application. Data access and collaboration. To address the routing problem in the ever-changing roads of Doha, we partnered with the national taxi company Karwa. The collaboration gives us access to all taxi data (both historic and live) that took place in the country, including pick-up and dropoff locations, time, duration, O N D E CE MBE R 2 , 2010, Qatar was announced to host 2022 FIFA World Cup. That was time for celebrating the first-ever Middle Eastern country to organize the tournament. The 1.8M population of Qatar then (2.8M today) never imagined the journey their country was about to embarked. Indeed, in less than 10 years, the population grew by more than a half, pushing the available urban resources and services to their limit. At the same time, the country undertook an ambitious investment plan of $200B on various infrastructural projects including a brand new three-line metro network, six new stadiums, several new satellite cities, and an astonishing 4,300km of new roads, which tripled the size of the road network in only five years. While this enterprise boosted the socio-economical life of people in Qatar, it did disrupt the way they navigate the urban space and their mobility patterns in general. Simple commutes to work, drops and pickups of kids to and from schools, became challenging and impossible to plan with daily changes in the road layout, including temporary and permanent closures, deviations, new connections, conversions of roundabouts into signaled intersections, turn restrictions, to name but a few. A commute to school Traffic Routing in the Ever-Changing City of Doha