I have always been itching to make a graphic that shows the full network with the numbers which I have never been able to find.
I finally found a good reason to make this graphic after the govt officially notified a new numbering scheme for the NH network depending on its orientation and its geographical position. Of course this was done not through a map, but this ridiculously confusing pdf.
Using my old map of the Indian NH network on wikipedia as a base, i carefully plotted all the missing links and new highways on paper. It took around four days to get the entire schematic geometry in place using illustrator and another two days for the labeling and tweaking to produce this nifty graphic which highlights the new numbering scheme. Not only is this the first ever visualization of the new numbering scheme but also the most complete and updated map of the NH network you will find anywhere.
Apart from being a good visual reference, the map also helps to identify issues in the new numbering scheme caused by strictly following the east-west and north-south orientation rules. While on the plus side multiple highways have been renumbered into one contiguous chain like N44-Srinagar-Kanniyakumari, this has caused other popular highways to be truncated into multiple segments like the Chennai-Bangalore Old Madras Road via Chitoor (NH4) becoming N48-N40-N73-N75. Sometime you wonder if they conducted this whole renumbering exercise based on an excel sheet of highways rather than a map.
Available on wikipedia: