Speed restrictions were imposed on a section of the Delhi Metro's Blue Line today after maintenance work could not be completed due to heavy rains in the city last night. The temporary restriction between the Subhash Nagar and Tilak Nagar metro stations caused overcrowding during peak office hours as the frequency was one train in every 15 minutes. The average end-to-end speed of a Delhi Metro train is around 30 kmph, but on the Blue Line it was 15 kmph today. "Due to some planned periodic maintenance by the track department last night, temporary speed restriction (TSR) of 15 kmph has been imposed on Up line between Subhash Nagar and Tilak Nagar stations (going towards Dwarka), which is likely to continue for the day," a Delhi Metro Rail Corporation spokesperson said. This may result in minor delay on the line, he said. Maintenance of the line would have got completed in the night itself but continuous rain did not provide enough window to complete the work, the official said. The temporary speed restriction will be removed once the track department carries out the remaining work in the night, he said.