There isn’t an option to manage the delay in the System Preferences, however, you can eliminate it with the following Terminal command;
defaults write com.apple.Dock autohide-delay -float 0 killall Dock
After you’ve executed these commands, the Dock will pop up at the slightest mouse movement on the Dock side of the screen. Of course, if it gets irritating, you can restore the delay with the following Terminal command;
defaults delete com.apple.Dock autohide-delay killall Dock
Eliminating the delay doesn’t have any effect on the working of the Dock and it is a mere change in the response time. Remember that the delay is there so that the Dock does not perceive a momentary mouse movement as a cue to reappear. It is reasonable that if you have the Dock set to the left side of your display, you will be less likely to accidentally make it appear and can use this tip without a worry.