Specifications include, but are not limited to: 3.2.3 Standards of Service. The standards of service prescribed herein are a minimum and are predicated upon reasonable and adequate advance notice to the carrier of service of services to be performed. In emergency situations, carriers will endeavor to comply with the prescribed standards as circumstances permit. 3.2.3.1 Passenger Comfort Needs. Motor coach buses must afford passenger comfort needs as follows: 3.2.3.1.1 Seat Specifications. Passenger seats must be of such design as to afford optimum comfort during movement, and include the following: Be upholstered with foam rubber or other material providing equivalent comfort which will prevent contact with structural parts of the seat bottom or back. Seats with shifted or excessively worn cushioning will not be acceptable, even if they otherwise meet the requirements herein. Be equipped with two padded arm rests of such density as will provide adequate vibration insulation and prevent the feel of any arm cap protuberance through the padding. Be of minimum width of 37 ½ inches for double seats (2 passengers) and 16 ½ inches for single seats. (Equipment presently configured at 34 inches for double seats and 16 ½ inches for single seats remain acceptable.) Be capable of reclining to 30 degrees, except that seats immediately ahead of lavatories or those in the extreme rear of the coach need not conform to this requirement. The degree will be measured from a line perpendicular to the floor to a line tangent to the front surface of the seat back fully reclined. The seat adjustment lever for each passenger will be located conveniently for the use of the seated passenger and designed so it will not present a hazard to the occupant when seated or when entering or leaving the seat.