The Noodle Box in British Columbia, has an interesting allergy statement regarding nuts. Many of us have seen "nut free" or confining nuts to an area of a restaurant. We have seen clearly spelt out in restaurant guides that they have nuts in their kitchen and too many cross contamination issues for the nut allergic to safely eat.
The Noodle Box is a small chain, that has Epi pens on site, and open about grinding nuts in the kitchen. I don't think any nut allergic person would feel comfortable with this, as grinding by nature puts nut particles in the air.
The idea of the restaurant having an epi pen sounds good, as a back up, but it should remain the allergic persons obligation to carry their own epi pens.