First of all: People will smile at you everywhere! They are not used to Western people driving a Tuk Tuk, but find it very funny... Furthermore you are very agile, can stop everywhere and if you
don't drive very long distances on one day, it's comfortable enough.
Most important thing when driving a Tuk Tuk: Don't speed! I normally drive between 30 and 40 km/h, according the traffic signs you are not allowed to drive faster.
Beware of Buses and Lorries, always keep an eye on them and give them as much space as they need. But as long as you cruise slowly, you actually don't have to worry. The main roads in Sri Lanka
are in a good condition, they even have crosswalks. Except of Colombo, the roads have a quite rural character. Therefore I would recommend to start the tour not directly in Colombo.
There is a wonderful train journey from Colombo via Kandy to Ella, I recommend to combine it with a Tuk Tuk tour to the south coast.
After your train journey to Ella, we will deliver the Tuk Tuk to your Hotel in Ella. From Ella you can drive down to the national parks Udawalawe and Yala. After these Safari adventures you can
proceed your journey all along the coast up to Negombo Beach, where you can return the Tuk Tuk and are already close to the airport.