Questions about Visa and Travel Document Requirements when travelling between Uganda, Rwanda, Kenya, Tanzania, Burundi. do I need a visa when crossing from one country to another? How do I cross borders with my own vehicle?

a) Do I need a visa to travel from one EAC country to the next?
If you are a citizen of any one of the five EAC Partner States of Burundi, Kenya, Rwanda, Tanzania and Uganda, you won’t need a visa to travel to any of the countries within the EAC bloc. For visitors from without East Africa, please check individual EAC Partner State Immigration/Home Affairs websites for visa information. Otherwise the basic rule is a visa acquired from one country does not apply to another and once you exit one country, you shall need to apply for another visa when re-entering it.
b) Which documents do I need to carry along with me when travelling to any EAC state?
Standard travel documents such as national passports apply for East Africans and non-East Africans alike, although East Africans may use the East African Passport or temporary travel documents in place of either national or East African passports.
c) I would like to use my vehicle in another EAC country; what should I do?
East Africans are allowed to drive private cars across borders and across the entire EAC region, free of charge, for visits no longer than seven (7) days.  All you have to do is fill a form, obtainable at border crossing points, which grants you the free access. Generally speaking, you need to have a COMESA Insurance which can be purchased from any major insurance companies or even at most border crossing points, your original driver’s license, and original copies of your vehicles owner’s logbook.
d) Do I need to acquire a local driver’s license to drive my car in another EAC state?
Citizens of EAC states need not acquire a new license to drive in another EAC country. Driver’s licenses from any of the Partner States apply anywhere in the EAC region. Suffice it to say that your license must be valid.
e) As a resident of East Africa, can I use my current mobile phone number when I travel through the region?
Yes. Thanks to a series of inter-operator roaming agreements, East African residents may continue to use their local mobile phone numbers, sometimes without incurring roaming charges. *Please check the availability of this service with your operator.
f) What should I do if I lose my travel documents while visiting another country?
If you lose your travel documents, report to the nearest police station as soon as possible. With the Police’s help you should be able to access temporary travel documents from your country’s diplomatic mission.
g) I am a citizen of Tanzania living in the United Kingdom, I have UK  right of abode in my United Republic of Tanzania passport, do I need a visa to visit Kenya, Rwanda, Burundi or Uganda? – Carlos Montana

A citizen of any of the East African Community Partner States (Burundi, Kenya, Rwanda, Tanzania and Uganda) does not require a visa to travel to or through East Africa. Also note that East African citizens pay the same rates as locals in a given EAC country to access any tourist or accommodation facilities.