The data shown here represents the changing ride quality of RS routes since 1988 as measured by the International Roughness Index (IRI). IRI values increase as roughness levels increase. Consequently, lower numbers on this chart represent smoother pavements.
YEAR |
|
IRI MP |
|
YEAR |
|
IRI MP |
1988 |
|
136 |
|
2000 |
|
137 |
1989 |
|
139 |
|
2001 |
|
136 |
1990 |
|
137 |
|
2002 |
|
135 |
1991 |
|
134 |
|
2003 |
|
135 |
1992 |
|
131 |
|
2004 |
|
133 |
1993 |
|
130 |
|
2005 |
|
132 |
1994 |
|
129 |
|
2006 |
|
129 |
1995 |
|
126 |
|
2007 |
|
130 |
1996 |
|
121 |
|
2008 |
|
129 |
1997 |
|
120 |
|
2009 |
|
127 |
1998 |
|
136 |
|
2010 |
|
132 |
1999 |
|
136 |
|
|
|
|