Mumbai Local - RailFanning nirvana.

If you consider any pair of daily running train with N number of rakes. A train departing from source will cross its counterpart for N-1 times till it reaches destination.
Take Awadh Assam express. It has 7 rakes. Hence, 15910/09 Lalgarh - Dibrugarh Avadh Assam crosses counterpart 6 times. Aprox location and timing:
1. Sangariya (Between Hanumangarh & Bhatinda) 23.45 (Day 1)
2. Moradabad...
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11.15 (Day 2)
3. Gorakhpur 23.30 (Day 2)
4. Kharik (Between Mansi & Katihar) 11.30 (Day 3)
5. Barpeta Road 00.00(Day 3/4)
6. Mahutgaon (Between Simaluguri & Tinsukia) 12.40 (Day 4)
Crossings for Kerala Express:
NDLS bound Kerala Express crosses TVC bound Kerala Express, considering all the rakes are running dot on time:
Day 1:
1. Between Kollam and Kayamkulam Junction
day 2:
2. Near Jolarpettai
3. In BZA-WL stretch
day 3:
4. Near Itarsi
5. Last one between Mathura and Faridabad.

DBRG bound Brahmaputra mail will cross its counterpart 5 times:
1. Between Aligarh and Tundla(day 2)
2. Near Ara(day 2)
3. Near Harishchandrapur in Malda town- Barsoi stretch(day 3)
4. Between Rangiya and Kamakhya(day 3)
5. At Bhojo(day 4)