Road Spikes is a road item that made its debut in Bloons Tower Defense 2 and have been in every subsequent Bloons TD game since. Road Spikes are a group of spikes which pop up to 10 (11 in BTD 5 Flash) bloons upon impact. Road Spikes only last until the end of the round. In Bloons TD 3 there is a number indicating how many spikes are left, with each spike popping 1 bloon, while in later games, it degrades. Road Spikes will disappear at the end of the round if not completely used up. Road Spikes cost 25 on Easy Difficulty, and 30 on Medium and Hard. The prices are the same for every game that Road Spikes are in. In Apopalypse Mode, Road Spikes and Monkey Glue last for an indefinite time since there are no round endings. Road Spikes are best used for popping Bloons that escape your defenses because they don't earn enough money to pay back their purchase.
In Bloons TD 2, Road Spikes have different sprites for its icon: before placing down and after.
An entire pile will pop the outer layer of lead bloons when it is put under 0|3 village, leaving two unharmed black bloons.
Technically, Road Spikes shouldn't even hit the bloons since they are floating (Unless they roll down the track like balls, but even so they should still be missing the blimps).
In some cases, if the Road Spikes are not spread out, it can cause a bloon's descendents to spawn in front of the spikes, causing them to not be popped. Therefore, clicking on a Yellow Bloon with a pile of spikes might cause a Green Bloon to leak.
Avoid placing excessively high amounts of Road Spikes along the track against Lead Bloons, such as in the picture of Park Path covered in Road Spikes. The Lead Bloons would just "eat" its way through every single Road Spike if you do.
This will make Road Spikes get $44, while they cost $30, giving you a free $14 cash if you popped all the bloons.
In Bloons TD 4, Road Spikes always show on the track in the same positions, but in Bloons TD 5, they rotate before being placed again, and after being placed once, they are return to the former position.
With the place tower anywhere glitch, it is possible to place Road Spikes off the track.
In Bloons TD 5, every other time, the spikes set changes when you place it.
In Bloons TD 5, if you have an activated Spikes R Us Speciality Building with the third upgrade, you get 1 free set of road spikes every round.
In Bloons TD 4, there is a glitch where fast Bloons can travel a short distance over road spikes before popping, causing the bloons that spawn from them to miss the Road Spikes completely.
In Bloons TD 3, the Road Spikes have a number displayed to the player of how many spikes are left.
In Co-Op Mode, you can place Road Spikes, but they often take too much time to load, and when they loaded, they would have already leaked. In BTD5, the left player sees the bloons correctly, the right player sees bloons with time delay, so only the left player should use Road Spikes. All players sees the bloons correctly in BTD6.