why do some trucks/vans have a button in addition to keyed ignition?

[sao123]

why do trucks and vans have the little silver button which must be pressed simultaniously with turning the key to start the engine?
why isnt the key good enough? i dont get it.

 

[Quixfire]

I'm not aware of any vehicles built from the factory that way. Are you sure it's not some aftermarket alarm system?

 

[Saint Nick]

my cavalier has a button i have to hit in order to get the key out of the ignition

 

[sao123]

most cargo & 10 passenger vans are equipped with these from the factory

 

[0roo0roo]

seems like overcomplication

 

[sao123]

after doing some searching, it appears this feature is a safety feature. found is most commercial vehicles...

snow plows. tractor trailers. commercial vans. etc.

 

[Zenmervolt]

Happens a lot with diesels, especially older ones with glow plugs where you have to turn the ignition on and then wait 30-60 seconds for the glow plugs to heat up before the engine can be started.

ZV