Google staticmaps <img> example encoded enough?

[jid...@jidanni.org]

Gentlemen, at
http://code.google.com/apis/maps/documentation/staticmaps/#EncodedPolylines
we observe the Google authors embedding plenty of dubious raw characters
into their <img> tag, <img src= ... }vXaj\h`]ovs@?yi_@r ... alt="Alaska Highway" />
My question is should I just do like them, or should I first run my
string through (which) one of
http://www.w3.org/TR/xpath-functions/#func-encode-for-uri
http://www.w3.org/TR/xpath-functions/#func-iri-to-uri
http://www.w3.org/TR/xpath-functions/#func-escape-html-uri ?
I mean how can I doubt Google?

[jid...@jidanni.org]

OK, I'll pick encode-for-uri()! as only it zaps "@", which is not
allowed, according to
http://en.wikipedia.org/wiki/Query_string#URL_encoding
(despite http://tools.ietf.org/html/rfc3986 saying
pchar = unreserved / pct-encoded / sub-delims / ":" / "@"
query = *( pchar / "/" / "?" )
)