That little strip of concrete or asphalt that connects the surface street to the freeway? That's called the "On Ramp". The purpose of the onramp is to allow your wheezy family bus to chug up to something approaching combat speed so that you can merge safely into the traffic on the freeway, instead of just standing there like a duck in thunder, watching the cars whiz past you.
To do this you must press down on the accelerator. If you are in a pickup, station wagon, diesel vehicle, Prius, or other such conveyance, you may need to push the accelerator all the way down to the floor to be at a reasonable speed by the end of the onramp. (The accelerator is the long, skinny pedal on the right, for those of you who are a little confused and hit the brake at the end of the onramp. )
If you follow these instructions, the crazy lady in the BMW behind you will not still be in second gear(!) at the top of the onramp, and have to blow past you in a squeal of rubber and vitriol, which I'm sure is a little disconcerting.
Also, the yellow speed signs on cloverleafs are not speed limits. They are suggested safe speeds. What they don't tell you is that 25mph is the suggested safe speed for a Corvair with shot ball joints on bald retreads after a Crisco tanker has overturned on the roadway. Normal vehicles can probably edge up to 30 or 40mph without the driver spilling their decaf latte all over their Blackberry.
That is all.