the holy sites. One of Saudi Arabia's most sophisticated bus networks is that of the city of Medina, with 10 lines connecting different regions of the city. It serves approximately 20,000 passengers on a daily basis. SATPCO buses are gender-segregated. Taxis are available in all major cities of the kingdom, in addition to the presence of private companies that offer vehicle hiring services, such as Uber and Careem, which is a subsidiary of Uber. A reflection of gender inequality, men travelling solo may sit in the passenger seat, but women are expected to sit in the rear seat. Before the reform in early 2020, Saudi cabs did not have meters; the price was agreed to up front and trips had to be booked in advance because of a 2012 "no hailing" regulation. Women had also been required to be accompanied by a male relative or another woman. The Makkah Mass Rail Transit, also known as Mecca Metro, became the first rapid transit system to enter operation in Saudi Arabia after the completion of the Al Mashaaer Al Muqaddassah (S) line in 2010. Other rapid transit systems currently in development in the kingdom include: The Riyadh Metro, consisting of six lines to serve the capital city of Riyadh, which is expected to open in 2021. A three-line metro project in extension to the public transportation master plan in Medina, announced by the MMDA in 2015. The Jeddah Metro, under construction with projected completion in 2025, as of 2018. Road transportation Highway network The Ministry of Transport in 2014 maintained a total estimated road length of 627,000 km, of which 151,000 km were highways linking major regions of Saudi Arabia with international borders and serving as interconnecting roads between the major Saudi Arabian cities; 102,000 km were secondary roads linking major cities with other smaller cities in their respective provinces; 374,000 km were feeder roads branching out of secondary roads and serving towns, villages & agricultural areas. Another 204,000 km of roads was under construction by the end of fiscal year 2014. The Ministry of Transport maintains 151,000 km of major roads linking the major Saudi Arabian cities and the kingdom to its neighbors. Most of these highways are two-lane highways, and some of them are not separated by median strips. The Ministry of Transport has been working on a project to gradually modernize these roads. Saudi Arabia's Highway 10 currently holds