प्रयागराज एक्सप्रेस - जो भी हो तुम खुदा की कसम; लाजवाब हो

During foggy weather, NDLS - SVDK Vande Bharat is getting regularly delayed. Just wondering if there's a speed restriction or caution order on run during early morning/late night runs?
For instance, I spotted this train crossing Rajpura last night at a slow speed in moderately heavy fog.

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