The speed limits in Nicaragua are 40 km/h (25 mph) or 60 km/h (37 mph) in built up areas, outside built up areas all roads are limited to 80 km/h (50 mph)
All of the road signs for the main roads are Green with White writing and the local roads are White with Black writing.
The main roads in Nicaragua are either tarmac or concrete and they are all generally very good and well maintained. There are also some smaller roads that are constructed of concrete paving blocks which, when new, are good but they can be a little bumpy and have loose blocks in the corners when they are old. There are also some long stretches of gravel roads in the the more remote areas of the country.
Petrol at the time of writing was about 1.35 US Dollars per litre.
Nicaragua has a very small police presence on the road and I never saw a police speed trap or a patrolling police car looking for speeding vehicles. However, like Panama there are frequent police and military checkpoints on most of the major roads.
To buy a SIM card for a mobile phone you need to go to any shop that has the Tigo or Claro mobile phone network sign outside it. I bought a SIM card at the border for 10 US Dollars (350 Cordobas in local currency) and that gave me 5GB of data for 7 days. No ID is required to buy a SIM card. The card can be topped up at any shop with the relevant sign outside it.
When entering Nicaragua you are required to purchase mandatory vehicle insurance and when I did this it cost me 12 US Dollars for 30 days of cover. I bought the mandatory insurance and the TIP was issued to me for 3 US Dollars for 30 days. You also have to pay Tourism tax of 3 US Dollars and you have to get the bike fumigated and this cost 4 US Dollars.
The entry procedure is fairly straightforward but it is labour intensive and prolonged and the whole process is detailed in my main blog post here.