Was Crocodile stronger at Marineford? Or was he holding back in Alabasta?

 During the Alabasta arc, Crocodile displayed a level of power that was initially considered overwhelming by the Straw Hat Pirates. He possessed the Logia-type Devil Fruit called the Suna Suna no Mi (Sand-Sand Fruit), which granted him the ability to control and transform into sand. He had a reputation as a Shichibukai and controlled the desert kingdom of Alabasta from the shadows. His strength was showcased through his battles with Luffy and others. At Marineford, Crocodile was present as part of the war that took place at Marine Headquarters. While he did participate in the battle, he didn't display the same level of dominance as some other powerful characters present. This has led fans to speculate that he might not have been as strong as initially portrayed in Alabasta. It's important to note that power scaling and character abilities can be subject to interpretation and development by the author. Oda often keeps details deliberately open-ended to keep the story intriguing.

Who invented the road that we can travel on?

 The concept of roads, or paths for traveling on land, has been around for thousands of years. Throughout history, humans have built roads for various purposes, including transportation, communication, trade, and military operations.

One of the earliest known roads was the Royal Road of the Persians, which was built in the 5th century BCE and stretched from Susa in modern-day Iran to the Mediterranean Sea. This road was used for the transport of goods and messages and was an important part of the Persian Empire's communication and trade network.

Other ancient civilizations, such as the Romans and the Chinese, also built extensive road networks for transportation and communication purposes. The Romans, in particular, were known for their well-constructed roads, which were used to transport troops, goods, and messages throughout the Roman Empire.

In modern times, roads continue to be an important part of transportation systems around the world. They are used to connect cities, towns, and other areas and facilitate the movement of people and goods.

Overall, the concept of roads has been around for thousands of years and has been used by various civilizations for transportation, communication, trade, and other purposes.