Guildford is a town in Surrey. It has claimed to be the county town on occasion instead of Kingston-upon-Thames.
Historically, Guildford is on the point where the River Wey passes through the North Downs. Both of these later had important, busy routes built on them - the Portsmouth Road for the historic naval base (now the A3) and the Pilgrims or North Downs Way between Winchester and Kent (now the A31 and A25)
Although the A3 is successfully dualled and almost totally grade-separated through Guildford, it is not built to modern standards. The stretch between the A322 and the A31 opened in 1934 and shows this the most: at rush hour the speed limits and closely spaced exits really slow it down. Other parts of the bypass to the east and south have since themselves been bypassed to higher quality standards.
Nowadays, the historic A3 is numbered the A3100, despite being in Zone 2 (originally the A3100 number applied to the bypass while the road through the town remained A3, common with early projects up to the 1930s, and was later swapped). The High Street is closed to traffic, so the A3100 is divided in two in the centre of the town. The historic road to Farnham, The Mount, is also closed to traffic since the construction of the Hogs Back route.
Thankfully, Guildford Town Centre is generally not too much of a nightmare. The A322, A320 and A25 are all on the North East side of town, so traffic can easily reach the A3. Of the other routes, the A3100 is for local traffic only, the A246 multiplexes with the A25 further out of town and the A323 isn't shown on signs much (since the contruction of the A331, it is quicker to travel via the A31 to get to Aldershot). The only road far away from the A3 is the A281 but thankfully, the A248 and B3000 relieve it of some of its traffic.
The reason there is no real wide bypass of Guildford is the terrain. Outside of the Wey valley, the land is much more hilly, thanks to the North Downs, and there are fierce objections to constructing one. However, the A3's route has gradually improved elsewhere from the 1970s onwards; with the completion of the Hindhead Tunnel in 2011, the Guildford Bypass is now the worst quality section of the A3 between the M25 and A27.