Roadblock
A roadblock in Iowa
A roadblock was a type of barricade that was designed to block all traffic on a road. Metaphorically, it could refer to any obstacle that stood in the way of one's goals.
In the alternate reality in the 2240s, there was a roadblock on an Iowa road leading toward a large stack of hay bales. Jim Kirk was joyriding his stepfather's Corvette when he passed the road where the roadblock was. (Star Trek)
In 2259, sometime after Spock was transformed into a full-blooded Human, he asked Doctor Joseph M'Benga if he and Nurse Christine Chapel were making any progress on developing a cure, so he could be restored to his Vulcan-Human hybrid appearance once again. M'Benga however told him that they had hit a roadblock. (SNW: "Charades")
In 2371, when The Doctor was taken offline by a Komar, Captain Janeway asked Ensign Kim if he was able to get him back online yet, but he told her "whoever did this put up one hell of a roadblock." (VOY: "Cathexis")
In 2376, Alice described the real Tom Paris, who wished to escape her clutches, saying, "Life throws up a few roadblocks and he heads for the nearest exit." (VOY: "Alice")