Delhi is under a heightened security alert as the capital prepares to host top world leaders for the 18th BRICS Summit at Bharat Mandapam this weekend, with thousands of security personnel deployed and temporary traffic restrictions expected across key routes.Around 15,000 Delhi Police personnel, 200 companies of paramilitary forces and more than 500 CCTV cameras have been deployed as part of the security arrangements for the two-day summit beginning Saturday.Also Read: BRICS Summit in New Delhi: The grand finale is India's moment to navigate a bigger, and more divided blocDelhi Traffic Police has said there will be no shutdown of the city, but commuters should expect temporary stoppages, diversions and restrictions along routes used by VVIP convoys.Traffic will continue to move normally wherever security arrangements permit, officials said. However, stoppages during the movement of foreign dignitaries will not follow a fixed schedule, with vehicles to be released in phases depending on the security situation and prevailing conditions on the ground."We have made elaborate arrangements by ensuring minimum inconvenience to the public. We have also issued advance advisories on traffic arrangements," a senior police officer said.Russian President Vladimir Putin arrived in Delhi early Friday for the summit, while China has confirmed the participation of President Xi Jinping, his first visit to India in seven years.Among the other leaders expected to attend are Iranian President Masoud Pezeshkian, South African President Cyril Ramaphosa, Egyptian President Abdel Fattah El-Sisi, Abu Dhabi Crown Prince Mohamed bin Zayed Al Nahyan, UN Secretary General Antonio Guterres and WHO chief Tedros Adhanom Ghebreyesus.Over 35 roads could see restrictionsDelhi Police has surveyed the routes identified for the summit and held coordination meetings with multiple agencies and neighbouring states to prepare for the movement of foreign dignitaries.The security arrangements will cover the airport, hotels, Bharat Mandapam and other locations that visiting leaders are scheduled to travel to.In the New Delhi zone, more than 500 CCTV cameras, including high-resolution cameras, facial-recognition systems and vehicle number plate-reading cameras, will provide round-the-clock surveillance through a central monitoring room, officials said.Enhanced access control, verification, intelligence gathering, traffic management and emergency response systems have also been put in place at the summit venue and hotels where foreign dignitaries will stayAlso Read: BRICS by BRICS: India's journey from seeking reforms to shaping global orderMore than 35 roads could be affected during the summit, with key routes including Mathura Road, Sardar Patel Marg, Shanti Path, Janpath, Ashoka Road, Barakhamba Road, Tolstoy Marg, Africa Avenue Road, Niti Marg, Panchsheel Marg and APJ Abdul Kalam Road.The restrictions are expected to have a greater impact on commuters travelling between Noida and central Delhi, east Delhi and central areas, as well as those travelling from Dwarka and west Delhi towards Dhaula Kuan, the airport and south Delhi.Traffic movement in south Delhi could also come under pressure as the Egyptian delegation travels between its hotel in Saket and central Delhi, particularly during peak hours.Multiple VVIP movements expected each dayThe scale of the summit means Delhi could see dozens of high-security movements every day, officials said.A visiting leader may travel between the airport, hotel, Bharat Mandapam and venues for bilateral meetings and other engagements. This could result in around 70-80 or more high-security movements across the city in a single day.Each movement requires separate traffic regulation, access restrictions and coordination along the designated route, officials said, making the traffic impact significantly greater than that of a routine VIP visit.The city got a preview of the arrangements on Wednesday evening when a motorcade rehearsal resulted in prolonged traffic delays at several locations.Traffic was regulated at 22 diversion points during the rehearsal, which was held between 7 pm and 10 pm.Nearly 4,800 traffic personnel have been deployed specifically for summit-related arrangements, officials said.Metro, buses to operateThe Delhi Metro will continue to operate during the summit, although temporary restrictions may be imposed at some stations or on particular entry and exit gates if required for security reasons.DTC and other city buses will also continue to run, but services passing through affected areas may be diverted, curtailed or regulated depending on the movement of VVIP convoys.Autos, taxis and app-based cab services will remain operational, though their access to controlled or restricted zones and pick-up and drop-off arrangements could be affected.Candidates appearing for examinations such as UPSC, NDA and CDS have been advised to check their examination centres and routes in advance, carry their admit cards and identification documents and leave early to account for possible delays.People travelling to hospitals for planned appointments have similarly been advised to allow additional time and check their routes beforehand. In case of a genuine medical emergency, commuters should immediately alert nearby traffic personnel.Traffic authorities have also coordinated with online map service providers so that restrictions, diversions and alternative routes can be reflected on navigation platforms in real time.Parking will not be permitted on restricted and security-sensitive roads. Essential services, including the movement of milk, medicines and other supplies, will be facilitated under the applicable arrangements.Police have also appealed to residents not to circulate unverified social media messages claiming that Delhi will be under a "Delhi bandh" or that roads across the city will be completely shut.Officials have urged commuters to rely only on official advisories for information on traffic restrictions during the summit.