The most trips you can make to uganda and and back are 4 per month. That is, if everything moves smoothly. Otherwise most drivers only manage 3 per month. Also hapo kwa salary, they don't make that much.
Kazi ya Kuendesha long distance trucks pays extremely well. Nasikia trip moja for Mombasa to Uganda you can be paid 100K. This is a two days journey. So you are making about Ksh 50,000 per day. Per month you can bag close to 1M if you make about 10 trips. Lakini pia kuna challenges. Talk a look at this video.