Allow 2.5 hours from the border at Mexicali to the Arches in San Felipe. Speeds of 70-80 mph are routinely possible in many stretches and on the four lane sections south of the Ensenada Road junction it is easy to find yourself doing 100 mph.
Note, however, that the posted speed limits on this excellent highway range from 80 kph (50 mph) to 110 kph (70 mph).
Highway patrol police will give you a ticket and escort you to the bank in San Felipe or Mexicali to pay it immediately. There is a long, straight stretch of road between km 70 and km 90 which marks the causeway over the great Laguna Salada.
The road is elevated several feet above the lake bed and there are no shoulders!! Many years ago (in the 1980's) the Laguna was routinely flooded by the waters of the Colorado and was one of the most spectacular stops on the winter flyway for migrating birds.
Now we have only the dry lake bed and it can be plagued with dust devils or small tornadoes (tolvaneras) on hot summer afternoons.
Be very careful if there are signs of a sandstorm ahead. Visibility can drop to near zero in a few hundred meters and your vehicle can be buffeted by very strong winds.
One of the most dangerous features of a sandstorm is that large drifts of sand can pile up on the road. If you hit one of these drifts at any speed over 30 mph you stand the chance of your car overturning or drifting off the road and down the precipice onto the dry lake bed.
There is currently only the permanent military checkpoint at the junction with the Ensenada Road where checks for drugs and guns are always made in both directions. With the new emphasis on security, random military checkpoints are being set up, often just for a few hours at a time, to catch drug smugglers.
On busy weekends, the traffic north can be significantly delayed by these checkpoints. Remember there is no gasoline or diesel fuel available in the 130 mile stretch from Mexicali to San Felipe.