It is really annoying that I can not restructure a city because human competitor in multiplayer mode put his road inside. Is it any option to disable remove others road?
In a multiplayer game against human components, there is no legitimate way for you to remove another player's tiles as a different company.
Depending on your morals, there is however another way. In multiplayer, multiple people can control one company and during a game you can switch which company you are playing for. Provided that the company whose tiles you wish to remove does not have a password set, you can join their company, remove the tiles which are in your way and then rejoin your own company.
Of course, the players for the company whose tiles you removed will likely be angry and you'll probably find yourself removed from the server. To stop something similar from happening to your own company, always set a company password and only share it with those you trust!
In the end, the method that's most likely to produce results without annoying others is simply to talk to them and ask them to remove the offending tiles.
Things are slightly different however in a singleplayer game. The only legitimate way to remove a competitor's tiles is to purchase all of the company's shares, or have them go bankrupt. Depending on which AI you're using, they may also remove tiles themselves.
If you're willing to cheat however, you can open the Cheat menu (Control + Alt + C) and use the "Playing as company" option to switch to the competitor whose tiles you wish to remove. Once you're done, use the same cheat option to switch back to your own company. Note however that, as noted in Cheat menu, the game will permanently remember that you've cheated and will keep the tick mark next to any cheat options you've used - even if you restore them back to default.