M27 motorway

Key takeaways

M27 motorway belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect M27 motorway to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of M27 motorway from memory before moving on to harder problems.

Reference excerpt

The M27 is a motorway in Hampshire, England. It is 27.9 miles (44.9 km) long and runs between Cadnam and Portsmouth. It was opened in stages between 1975 and 1983, providing the largest two urban areas in Hampshire (Southampton and Portsmouth) with a direct motorway link. An extension into the county of West Sussex was planned but never constructed.A number of smaller motorways were proposed, connecting the city centres of Southampton and Portsmouth to the motorway; of these only the M271 and M275 were built. Three sections of the M27 have since been widened to four lanes each way, the first between junctions 7 and 8, the second between junctions 3 and 4, and the third begins at the slip road where junction 11 joins until mid-way to junction 12.

Route Running approximately parallel both to the coast of the Solent and to the A27, the M27 starts as an eastwards continuation of the A31 from Bournemouth and Poole, at Cadnam in the New Forest. The motorway meets the A36 from Salisbury, crosses the Wessex Main Line railway, and then meets the M271 to central Southampton. After the M271, the road becomes a dual four lane motorway and passes Rownhams services, it then meets the M3, (two lanes going off, two lanes continuing to the other side of the junction) reverting to a dual three lane motorway as it passes to the north of Southampton, passes Southampton Airport, meeting junction 7 and becoming dual four lanes again, then becoming dual three lanes after junction 8, it then runs alongside the West Coastway Line as it heads south-east towards Fareham. It then runs alongside the northern outskirts of Fareham, briefly with a fourth climbing lane in either direction, before its junction with the M275 to Portsmouth. Very shortly after this point the motorway ends, becoming the A27, a four lane dual carriageway almost to motorway standards until the junction with the A3 (M) motorway. The official reason for this section of road not being a continuation of the motorway is the hard shoulders being too narrow. Although the M275 which the M27 junctions with, has no hard shoulders along its entire length.

History

Opening dates The M27 was opened in stages (in common with many UK motorways) between 1975 and 1983.

Junction 1 to 2 opened 20 August 1975 Junction 2 to 4 opened in December 1975 Junction 4 to 7 opened in 1983 Junction 7 to 8 opened in February 1978 Junction 8 to 12 opened in March 1976 The South Stoneham Crematorium, which was located north of South Stoneham Cemetery, was demolished during 1973 to make way for the construction of the M27 motorway. The South Stoneham garden of remembrance is now located at the north end of the cemetery, adjacent to the motorway.

Unfulfilled plans There were proposals, by the Institution of Highway Engineers in 1936, for a road that would run all the way along the south coast. The government in their Trunk Roads Act 1946 (9 & 10 Geo. 6. c. 30) established that there should be a trunk road between Folkestone and Honiton. The south coast road did not materialise, however the M27 was developed from these long standing plans. The termination of M27 at Cadnam was due to an understanding with the Verderers of the New Forest that the motorway should not run through the Forest. The M27 was meant to be extended to Chichester; a sign of this is the width of the A27 road between junction 12 and the junction with the A3(M), which has three or four lanes, a hard shoulder and grade-separated junctions. It is not part of the M27 as its hard shoulders are not quite wide enough to comply with motorway regulations. The M272 was meant to go from junction 5 through Portswood to the centre of Southampton. The M272 was instead built (in much-reduced form) as the A335 Thomas Lewis Way. Junction 6 was never built – there were plans for a motorway spur (probably to be numbered M273) connecting the M27 to the centre of the Townhill Park area of Southampton. The planned Meon Valley Services, service area just east of junction 9 was never constructed. The long westbound exit slip road at junction 9 was designed to allow an entry to and exit from the service area.

2015 incident In November 2015, an elderly woman died after falling from the A3057 bridge that crosses over the M27, into westbound traffic, just before junction 3. She had not taken her anti-psychotic medication, and escaped from her Southampton home through an upstairs window before climbing off the garage roof and running away.

Smart motorway conversion In March 2018, work began to convert the section between junctions 11 and 4 to a smart motorway. The scheme will turn the hard shoulder into a permanent fourth running lane, adding refuge areas along the route and installing new CCTV and speed cameras with mandatory variable speed limit signs. In early January 2019, official work began when average speed cameras were switched on between junctions 5 and 4. Average speed cameras further along on the scheme will be turned on as work continues along the route. The work has suffered repeated delays, originally due to be complete in spring 2021. The commissioning phase began in mid February 2022, during which time the smart motorway technology will be tested, including stopped vehicle detection radars. This is with a fully open carriageway and a 60 mph (97 km/h) speed limit controlled by electronic signs on new gantries and CCTV and speed cameras. The 60 mph limit was lifted on 29 June 2022 when the upgraded section was fully opened and returned to the national speed limit.

Junction 5-7 concrete overlay In February 2024, National Highways began a project to resurface the concrete section of the M27 between junctions 5 and 7. A 180 mm (7.1-inch) layer of low noise surface asphalt is being overlaid on top of the existing concrete surface, with the intent of improving the road surface and reduce road noise to neighbours of the motorway. A contraflow system is being used throughout the process and the project is due to be completed by Spring 2026.

Junctions

Data from driver location signs are used to provide distance and carriageway identifier information. Where a junction spans several hundred metres and start and end points are available, both are cited.

See also List of motorways in the United Kingdom

References

External links

The Motorway Archive – M27

Notes

Illustrations

Worked examples

Example 1 — a first encounter with M27 motorway

Start with the simplest possible case. Write down what M27 motorway claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to M27 motorway before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about M27 motorway ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of M27 motorway

In research: M27 motorway appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses M27 motorway in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: M27 motorway is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1975 establishments in England, Motorways in England, Roads in Hampshire, so understanding it makes those chapters shorter.
In everyday life: Look for M27 motorway outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study M27 motorway in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what M27 motorway means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain M27 motorway out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is M27 motorway in simple terms?

The M27 is a motorway in Hampshire, England. It is 27.9 miles (44.9 km) long and runs between Cadnam and Portsmouth.

Why does M27 motorway matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study M27 motorway?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on M27 motorway.