This is one of the worst and most incorrect travel books that is available about any country and that I encountered in decades of travelling and living in many countries around the globe. Too much 'information' is so wrong that it sometimes is even dangerous to rely on it, particularly in a country like Sudan. Where there is an established bridge the authors make you believe that one must take a ferry.
Apparently not too much has been corrected or even newly researched for this third edition, when one compares it to edition 1 of a few years back.
Information regarding how to reach sites frequently is so imprecise or missing at all that hardly anybody is ever able to locate a number of sites, instead the 'new' authors rely on taking a local ricksha or donkey cart to get you there. Certainly no traveller with his own vehicle will ever be able to locate a number of localities. Even some of the very few given GPS coordinates are not accurate. Several interesting locations are not mentioned at all. Road or track conditions are at times wrong or missing at all. Important accommodation facilities are unknown to that 'guide', which is inexcusable as Sudan doesn't have many possibilities anyway. Prices can't always be correct, so this is not criticised.
It appears that the new authors probably have visited the museum in Khartoum and otherwise were quickly, if at all, driven by some sort of guide to a few common places only, without grasping very much of what goes on and where they really are.
Save your money or at least be very careful when using that 'travel guide'.
Regrettably there are not many choices, or no other choices, when it comes to Sudan. A traveller to Sudan most probably has more adventurous and explorative characteristics than usual and therefore should be prepared better to `handle' that book, hopefully.
Background: I live in Sudan and have just finished another 4-week self-drive tour with my own 4x4 across all of Sudan, including severe desert crossings and to a number of places and regions that are not even mentioned in that book. It would have been quite hair-raising and at times dangerous having had to rely on that book, although each and every part of that `guide' was studied and verified when travelling and exploring.
Note: that 4-week tour was done alone with my wife, no guide whatsoever, no other vehicle, and no guidance whatsoever from anybody or any tour operator and it was wonderful.