Following a semicircular path along Budapest’s Grand Boulevard, tram lines 4 and 6 are the busiest in Budapest, covering a huge part of the city while calling at stops on both the Buda and the Pest side and transporting hundreds of thousands of passengers each day. Both trams originate from Széll Kálmán Square and cover almost the same route – major stops include Margaret Island, Jászai Mari Square, Nyugati Railway Station, Oktogon, Király Street, Blaha Lujza Square, and the Corvin Quarter – with their two end stations in south Buda being the only difference: tram line 4 ends at Újbuda Center, while tram line 6 concludes its journey at Móricz Zsigmond Square (although these two terminuses are just a mere 400 meters away from each other). According to city officials, the worn-out tracks must be replaced with a more modern structure that will last for many years to come, bringing about the need for this summer's renovation.
Please bear in mind that another major transportation line in the city, Metro Line 3, is also currently under renovation, which means that in the evenings and on weekends replacement buses operate on the whole line. During the day on workdays, metro cars circulate between “Kőbánya Kispest” and “Lehel tér”. Between “Lehel tér” and “Újpest-központ”, passengers can board replacement buses. Read this article for more details about the M3 Metro renovation project.